{"content_id":"ueq4dptr8g","slug":"guju-fortress-battle-1231-mongol-siege-process-and-outcome","locale":"en","schema_type":"Article","category":"case_study","category_name":"Case Study","title":"Battle of Guju Fortress 1231: Mongol Siege and Outcome","summary":"The Goryeo forces at Guju Fortress repelled repeated Mongol attacks in 1231. The battle ended the following year when the court made peace and the defenders surrendered by royal order.","sponsorship_disclosure":null,"affiliate_disclosure":null,"commerce_disclosure":null,"author":{"name":"Injoys Editorial Team","url":"https://injoys.com/ko/about"},"key_points":["The Battle of Guju Fortress in 1231 was a fortress defense against Mongol forces.","Park Seo assigned Kim Jung-on, Kim Gyeong-son and others to defend different sectors.","The Goryeo forces adapted their responses to the methods of attack and repeatedly repaired collapsed fortress walls.","Guju Fortress avoided capture but surrendered by royal order in 1232.","The successful defense of Guju Fortress did not end the Mongol invasion of Goryeo as a whole."],"content_markdown":"In 1231, Bak Seo, Kim Gyeong-son, and others at Guju Fortress resisted a Mongol siege. They prevented its capture by assigning defensive sectors to different units and repairing the walls. Although they surrendered the following year under royal orders, their defense is remembered for withstanding repeated siege attacks.\n\nThis article follows the biography of Bak Seo in Goryeosa, published on Our History Net, and was checked in November 2026.\n\n## The Difference Between the Battle of Guju Fortress and the Great Victory at Gwiju\n\nThe Battle of Guju Fortress was **a defensive battle against Mongol forces in 1231**. On Our History Net, it can also be found under the name Battle of Gwiju Fortress. It is separate from the Great Victory at Gwiju in 1019, when Gang Gam-chan defeated the Khitan army.\n\n| Category | Battle of Guju Fortress | Great Victory at Gwiju |\n| --- | --- | --- |\n| Main year | 1231, with the fighting ending in 1232 | 1019 |\n| Opponent | Mongol forces | Khitan forces |\n| Main commanders | Bak Seo, Kim Gyeong-son, Kim Jung-on, and others | Gang Gam-chan and others |\n| Main events | Defending the fortress against repeated siege attacks | Defeating the Khitan army that invaded Goryeo |\n| How to interpret the outcome | Consider both the successful defense and the later surrender | Recognize the victory over the Khitan army |\n\nThe distinction between these events is based on “Bak Seo” on Our History Net and the Great Victory at Gwiju chronology in the Korean History Database. [Our History Net, “Bak Seo”](https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110), [Korean History Database, Great Victory at Gwiju Chronology](https://db.history.go.kr/id/ch_012_1019_02_00_0010).\n\n## The Mongol Invasion and the Troops Gathered at Guju Fortress\n\nTroops gathered at Guju Fortress as Mongol forces advanced south. The Mongols invaded Goryeo in the 8th month of 1231. They cited the killing of the Mongol envoy Jeogoyeo in 1225 as their justification for the invasion.\n\n“The Mongol Invasions of Goryeo” on Our History Net also explains the broader background. It presents an interpretation linking the invasion of Goryeo to Mongol preparations to conquer the Jin dynasty. The envoy’s killing alone therefore cannot fully explain the causes of the invasion. [Our History Net, “The Mongol Invasions of Goryeo”](https://contents.history.go.kr/front/kc/printViewPopup.do?levelId=kc_i200800).\n\nGuju was an inland military stronghold in northwestern Goryeo. Bak Seo, the military commander of the Northwestern Region, established his defensive headquarters there. Kim Gyeong-son and others who had withdrawn from Jeongju joined troops from nearby areas.\n\n| Commander or troops | Role at Guju Fortress |\n| --- | --- |\n| Bak Seo | Commanding the assembled troops and coordinating the defense |\n| Kim Jung-on’s unit | Defending the eastern and western sides of the fortress |\n| Kim Gyeong-son’s unit | Defending the southern side of the fortress |\n| Select troops from Anbuk-bu, Wiju, and Taeju | Divided among three sides of the fortress |\n\nThis deployment assigned troops from several regions to different defensive sectors. It is one reason the defense of Guju Fortress cannot readily be described as the achievement of a single commander. The gathering and deployment of troops are explained in New History of Korea. [New History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”](https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026whereStr=).\n\n## A Battle Chronology from 1231 to 1232\n\nFighting at Guju Fortress recurred from autumn through winter in 1231. The surrender under royal orders is described as taking place in the first month of the following year. The months below follow the lunar calendar used in the records.\n\n| Period | Events at Guju Fortress and the Course of the War | Source |\n| --- | --- | --- |\n| 8th month of 1231 | Mongol forces led by Saritai invade Goryeo | Our History Net, “The Mongol Invasions of Goryeo” |\n| Early 9th month of 1231 | The siege of Guju Fortress and full-scale fighting begin | New History of Korea, “Victories at Gwiju Fortress and Jaju Fortress” |\n| 10th month of 1231 | Mongol forces attack again and damage the walls, which Goryeo’s defenders repair | New History of Korea, “Victories at Gwiju Fortress and Jaju Fortress” |\n| 11th month of 1231 | Walls damaged by pocha attacks are reinforced again | New History of Korea, “Victories at Gwiju Fortress and Jaju Fortress” |\n| 12th month of 1231 | Resistance at Guju Fortress continues while the Goryeo court negotiates peace | Our History Net, “Bak Seo” and “The Mongol Invasions of Goryeo” |\n| First month of 1232 | Guju Fortress surrenders under royal orders, as the first invasion moves toward its conclusion | Our History Net, “Bak Seo” and “The Mongol Invasions of Goryeo” |\n\nThis month-by-month chronology was compiled by comparing the accounts in New History of Korea and Our History Net. [New History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”](https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026whereStr=), [Our History Net, “Bak Seo”](https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110).\n\n## Responses to Encirclement and Siege Attacks\n\nGoryeo’s defenders adjusted their defenses to the Mongols’ methods of attack. Siege warfare means fighting to attack and capture a fortress. The biography of Bak Seo in Goryeosa describes attacks ranging from assaults on the gates to attacks using ladders.\n\n| Mongol method of attack | Goryeo’s response as recorded |\n| --- | --- |\n| Attacks on several gates | Dividing the defensive sectors and sometimes making sorties outside the fortress |\n| Approaching the base of the walls to dig tunnels | Blocking equipment used to approach the walls |\n| Attacking the walls with pocha | Launching stones from pocha atop the walls in response |\n| Attacks using fire | Using water mixed with mud or stored water, depending on the form of attack |\n| Approaching with siege ladders called unje | Blocking the ladders with daewupo fitted with large blades |\n\nHere, pocha refers to stone-throwing siege equipment. The name in the record cannot simply be equated with modern gunpowder cannons. Daewupo, too, is described in this record as a weapon fitted with a large blade. [Original Text of the Biography of Bak Seo in Goryeosa and Commentary from Our History Net](https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040).\n\n## How Wall Repairs and Royal Orders Changed the Course of the Battle\n\nThe key to sustaining the defense was immediately restoring collapsed sections of wall. Goryeosa describes repairs made whenever the walls were damaged. It also records that iron cables were used to reinforce them.\n\nDamage to the walls did not immediately lead to the fall of the entire fortress. The defenders repaired damaged sections and prepared for the next attack. New History of Korea highlights the residents’ role in this repair work. [New History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”](https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026whereStr=).\n\nThe turning point that ended the fighting was a royal order sent from the court. Bak Seo had earlier rejected an appeal to surrender conveyed in a document from Wang Jeong, Duke of Hoean. The following year, Choe Rim-su and Min Hui delivered the royal order.\n\n\u003e We have already sent Jeong, Duke of Hoean, to make peace with the Mongol army, and our three armies have also surrendered. Stop fighting, come out, and surrender.\n\nGoryeosa, volume 103, “Biographies” 16, “Bak Seo”: Choe Rim-su and Min Hui’s appeal to surrender.\n\nAfter repeated persuasion, Bak Seo surrendered under royal orders. The immediate reason the fighting ended must therefore be distinguished from the fortress falling through military action. These circumstances are recorded in the biography of Bak Seo in Goryeosa. [Our History Net, “Bak Seo’s Battle at Gwiju Fortress”](https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040).\n\n## The Battle’s Outcome and the Continuing Mongol Invasions\n\nGuju Fortress avoided capture, but its defense did not reverse the course of the war across Goryeo. Goryeo’s main army was defeated at the Battle of Anbuk-bu. When Mongol forces advanced toward Gaegyeong, the court sought peace.\n\n| What is being assessed | Confirmed outcome |\n| --- | --- |\n| The defense at Guju Fortress | Repeated Mongol attacks were repelled |\n| The end of fighting at Guju Fortress | Surrender under royal orders after the court negotiated peace |\n| The first Mongol invasion | Brought to a close by the Mongol withdrawal in the first month of 1232 |\n| The long war between Goryeo and the Mongols | Invasions and resistance continued afterward |\n\nHere, ganghwa means an agreement to stop fighting. It is a different term from the Ganghwa in the relocation of the capital to Ganghwa Island that same year. Goryeo moved its capital to Ganghwa Island in 1232. A second Mongol invasion followed that year. [Our History Net, “The Mongol Invasions of Goryeo”](https://contents.history.go.kr/front/kc/printViewPopup.do?levelId=kc_i200800).\n\n## How to Read the Numbers in the Records\n\nNumbers relating to the Battle of Guju Fortress must be read with attention to what they count. Treating the size of a particular unit as the entire fortress garrison changes the meaning. The duration of one round of fighting must also be distinguished from that of the battle as a whole.\n\n| Figure in the record | What the figure covers | Caution when interpreting it |\n| --- | --- | --- |\n| 30 days | One round of siege fighting before the Mongols withdrew | Not the entire period, including later renewed attacks |\n| About 250 men | Select troops from the Protectorate, Wiju, and Taeju | Not the total number of defenders at Guju Fortress |\n| 50 kan of wall | A recorded section of wall destroyed during a renewed attack | There is no basis for converting kan into an arbitrary number of meters |\n\nThese figures appear in the original text of Bak Seo’s biography in Goryeosa. The record also goes on to describe renewed attacks after the initial fighting. The beginning and end of the Battle of Guju Fortress therefore cannot be defined by the 30 days alone. [Our History Net, Original Text of “Bak Seo’s Battle at Gwiju Fortress”](https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040).\n\n## Records and Interpretations\n\n### What Is Directly Recorded\n\nThe main historical source is Goryeosa, volume 103, “Biographies” 16, “Bak Seo.” It covers troop deployments, responses to siege attacks, wall repairs, and surrender under royal orders. It also describes the circumstances of Bak Seo’s retirement to his hometown after the battle.\n\nIt also recounts a veteran Mongol commander’s praise for the defense. This should be read as an assessment included in Goryeosa. That statement alone cannot establish how this battle ranks against battles from other periods. [Our History Net, “Bak Seo’s Battle at Gwiju Fortress”](https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040).\n\n### Assessments Shared by the Historical Commentaries\n\nThe commentaries consulted recognize the successful defense of Guju Fortress. New History of Korea discusses the participation of both regional troops and residents. “Bak Seo” on Our History Net distinguishes the military achievement from the subsequent surrender.\n\nReading these accounts together also reveals the roles of people other than the commanders. Troops fighting in their assigned sectors and residents repairing the walls supported the defense. This explanation draws together the commentaries consulted; it is not a single view shared by all historians. [New History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”](https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026whereStr=), [Our History Net, “Bak Seo”](https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110).\n\n### What Remains Uncertain\n\nThe commentaries differ in their accounts of Bak Seo’s activities after the war. New History of Korea states that he was later reappointed to office. “Bak Seo” on Our History Net considers the timing of his appointment as munha pyeongjangsa uncertain. It also leaves unresolved whether the appointment was made during his lifetime or awarded posthumously.\n\nIt is therefore difficult to turn Bak Seo’s later life into a detailed chronology of his return to office. The records consulted also do not establish the total troop strength on either side. Nor is there any basis for adding accounts of Bak Seo’s feelings or speeches of encouragement absent from the records. [Our History Net, “Bak Seo”](https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110).\n\n## Why This Battle Is Studied as a Distinct Event Today\n\nThe Battle of Guju Fortress shows both local defense and national decisions about war. The successful defense of the fortress and the court’s decision to make peace were events at different levels. Both must be considered to understand the circumstances behind the eventual surrender.\n\nThe records of wall repairs also draw attention to the work that sustained the fighting. This perspective considers the commanders’ actions alongside the residents’ roles. These are details lost when military history is reduced to victories, defeats, and the names of individuals.\n\n## Frequently Asked Questions\n\n### Did Goryeo Win the Battle of Guju Fortress?\n\nThe defense succeeded in preventing the fortress from being captured. However, the defenders later surrendered under royal orders. The achievements of the local defense must be distinguished from the political conclusion.\n\n### Did Guju Fortress Refuse to Surrender to the End?\n\nIt did not give in to Mongol attacks or the initial appeals to surrender. However, it surrendered under royal orders in 1232. Any statement that it did not surrender needs to distinguish between these points in time.\n\n### Did the Battle Last Only 30 Days?\n\nThe 30 days refer to one round of siege fighting described in the record. The Mongols attacked again afterward. The full course of events must be considered from autumn 1231 to the first lunar month of 1232.\n\n### What Roles Did Kim Gyeong-son and Bak Seo Play?\n\nBak Seo commanded the troops gathered at Guju Fortress. Kim Gyeong-son’s unit was responsible for the southern side. Kim Jung-on’s unit defended the eastern and western sides.\n\n### Who Delivered the Royal Order?\n\nChoe Rim-su and Min Hui appear in the biography of Bak Seo in Goryeosa. They conveyed news of the court’s peace agreement and the surrender of the three armies. After repeated persuasion, Bak Seo obeyed the royal order.\n\n### Where Can the Original Text and Translation Be Found?\n\nThey can be found in “Bak Seo’s Battle at Gwiju Fortress” on Our History Net. The page includes the original text of Bak Seo’s biography from Goryeosa. A translation and separate commentary are also provided.","content_html":"\u003cp\u003eIn 1231, Bak Seo, Kim Gyeong-son, and others at Guju Fortress resisted a Mongol siege. They prevented its capture by assigning defensive sectors to different units and repairing the walls. Although they surrendered the following year under royal orders, their defense is remembered for withstanding repeated siege attacks.\u003c/p\u003e\n\u003cp\u003eThis article follows the biography of Bak Seo in Goryeosa, published on Our History Net, and was checked in November 2026.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#the-difference-between-the-battle-of-guju-fortress-and-the-great-victory-at-gwiju\" class=\"anchor\" id=\"the-difference-between-the-battle-of-guju-fortress-and-the-great-victory-at-gwiju\"\u003e\u003c/a\u003eThe Difference Between the Battle of Guju Fortress and the Great Victory at Gwiju\u003c/h2\u003e\n\u003cp\u003eThe Battle of Guju Fortress was \u003cstrong\u003ea defensive battle against Mongol forces in 1231\u003c/strong\u003e. On Our History Net, it can also be found under the name Battle of Gwiju Fortress. It is separate from the Great Victory at Gwiju in 1019, when Gang Gam-chan defeated the Khitan army.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eCategory\u003c/th\u003e\n\u003cth\u003eBattle of Guju Fortress\u003c/th\u003e\n\u003cth\u003eGreat Victory at Gwiju\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Category\"\u003eMain year\u003c/td\u003e\n\u003ctd data-label=\"Battle of Guju Fortress\"\u003e1231, with the fighting ending in 1232\u003c/td\u003e\n\u003ctd data-label=\"Great Victory at Gwiju\"\u003e1019\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Category\"\u003eOpponent\u003c/td\u003e\n\u003ctd data-label=\"Battle of Guju Fortress\"\u003eMongol forces\u003c/td\u003e\n\u003ctd data-label=\"Great Victory at Gwiju\"\u003eKhitan forces\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Category\"\u003eMain commanders\u003c/td\u003e\n\u003ctd data-label=\"Battle of Guju Fortress\"\u003eBak Seo, Kim Gyeong-son, Kim Jung-on, and others\u003c/td\u003e\n\u003ctd data-label=\"Great Victory at Gwiju\"\u003eGang Gam-chan and others\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Category\"\u003eMain events\u003c/td\u003e\n\u003ctd data-label=\"Battle of Guju Fortress\"\u003eDefending the fortress against repeated siege attacks\u003c/td\u003e\n\u003ctd data-label=\"Great Victory at Gwiju\"\u003eDefeating the Khitan army that invaded Goryeo\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Category\"\u003eHow to interpret the outcome\u003c/td\u003e\n\u003ctd data-label=\"Battle of Guju Fortress\"\u003eConsider both the successful defense and the later surrender\u003c/td\u003e\n\u003ctd data-label=\"Great Victory at Gwiju\"\u003eRecognize the victory over the Khitan army\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eThe distinction between these events is based on “Bak Seo” on Our History Net and the Great Victory at Gwiju chronology in the Korean History Database. \u003ca href=\"https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110\"\u003eOur History Net, “Bak Seo”\u003c/a\u003e, \u003ca href=\"https://db.history.go.kr/id/ch_012_1019_02_00_0010\"\u003eKorean History Database, Great Victory at Gwiju Chronology\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#the-mongol-invasion-and-the-troops-gathered-at-guju-fortress\" class=\"anchor\" id=\"the-mongol-invasion-and-the-troops-gathered-at-guju-fortress\"\u003e\u003c/a\u003eThe Mongol Invasion and the Troops Gathered at Guju Fortress\u003c/h2\u003e\n\u003cp\u003eTroops gathered at Guju Fortress as Mongol forces advanced south. The Mongols invaded Goryeo in the 8th month of 1231. They cited the killing of the Mongol envoy Jeogoyeo in 1225 as their justification for the invasion.\u003c/p\u003e\n\u003cp\u003e“The Mongol Invasions of Goryeo” on Our History Net also explains the broader background. It presents an interpretation linking the invasion of Goryeo to Mongol preparations to conquer the Jin dynasty. The envoy’s killing alone therefore cannot fully explain the causes of the invasion. \u003ca href=\"https://contents.history.go.kr/front/kc/printViewPopup.do?levelId=kc_i200800\"\u003eOur History Net, “The Mongol Invasions of Goryeo”\u003c/a\u003e.\u003c/p\u003e\n\u003cp\u003eGuju was an inland military stronghold in northwestern Goryeo. Bak Seo, the military commander of the Northwestern Region, established his defensive headquarters there. Kim Gyeong-son and others who had withdrawn from Jeongju joined troops from nearby areas.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eCommander or troops\u003c/th\u003e\n\u003cth\u003eRole at Guju Fortress\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Commander or troops\"\u003eBak Seo\u003c/td\u003e\n\u003ctd data-label=\"Role at Guju Fortress\"\u003eCommanding the assembled troops and coordinating the defense\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Commander or troops\"\u003eKim Jung-on’s unit\u003c/td\u003e\n\u003ctd data-label=\"Role at Guju Fortress\"\u003eDefending the eastern and western sides of the fortress\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Commander or troops\"\u003eKim Gyeong-son’s unit\u003c/td\u003e\n\u003ctd data-label=\"Role at Guju Fortress\"\u003eDefending the southern side of the fortress\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Commander or troops\"\u003eSelect troops from Anbuk-bu, Wiju, and Taeju\u003c/td\u003e\n\u003ctd data-label=\"Role at Guju Fortress\"\u003eDivided among three sides of the fortress\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eThis deployment assigned troops from several regions to different defensive sectors. It is one reason the defense of Guju Fortress cannot readily be described as the achievement of a single commander. The gathering and deployment of troops are explained in New History of Korea. \u003ca href=\"https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026amp;whereStr=\"\u003eNew History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#a-battle-chronology-from-1231-to-1232\" class=\"anchor\" id=\"a-battle-chronology-from-1231-to-1232\"\u003e\u003c/a\u003eA Battle Chronology from 1231 to 1232\u003c/h2\u003e\n\u003cp\u003eFighting at Guju Fortress recurred from autumn through winter in 1231. The surrender under royal orders is described as taking place in the first month of the following year. The months below follow the lunar calendar used in the records.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003ePeriod\u003c/th\u003e\n\u003cth\u003eEvents at Guju Fortress and the Course of the War\u003c/th\u003e\n\u003cth\u003eSource\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Period\"\u003e8th month of 1231\u003c/td\u003e\n\u003ctd data-label=\"Events at Guju Fortress and the Course of the War\"\u003eMongol forces led by Saritai invade Goryeo\u003c/td\u003e\n\u003ctd data-label=\"Source\"\u003eOur History Net, “The Mongol Invasions of Goryeo”\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Period\"\u003eEarly 9th month of 1231\u003c/td\u003e\n\u003ctd data-label=\"Events at Guju Fortress and the Course of the War\"\u003eThe siege of Guju Fortress and full-scale fighting begin\u003c/td\u003e\n\u003ctd data-label=\"Source\"\u003eNew History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Period\"\u003e10th month of 1231\u003c/td\u003e\n\u003ctd data-label=\"Events at Guju Fortress and the Course of the War\"\u003eMongol forces attack again and damage the walls, which Goryeo’s defenders repair\u003c/td\u003e\n\u003ctd data-label=\"Source\"\u003eNew History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Period\"\u003e11th month of 1231\u003c/td\u003e\n\u003ctd data-label=\"Events at Guju Fortress and the Course of the War\"\u003eWalls damaged by pocha attacks are reinforced again\u003c/td\u003e\n\u003ctd data-label=\"Source\"\u003eNew History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Period\"\u003e12th month of 1231\u003c/td\u003e\n\u003ctd data-label=\"Events at Guju Fortress and the Course of the War\"\u003eResistance at Guju Fortress continues while the Goryeo court negotiates peace\u003c/td\u003e\n\u003ctd data-label=\"Source\"\u003eOur History Net, “Bak Seo” and “The Mongol Invasions of Goryeo”\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Period\"\u003eFirst month of 1232\u003c/td\u003e\n\u003ctd data-label=\"Events at Guju Fortress and the Course of the War\"\u003eGuju Fortress surrenders under royal orders, as the first invasion moves toward its conclusion\u003c/td\u003e\n\u003ctd data-label=\"Source\"\u003eOur History Net, “Bak Seo” and “The Mongol Invasions of Goryeo”\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eThis month-by-month chronology was compiled by comparing the accounts in New History of Korea and Our History Net. \u003ca href=\"https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026amp;whereStr=\"\u003eNew History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”\u003c/a\u003e, \u003ca href=\"https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110\"\u003eOur History Net, “Bak Seo”\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#responses-to-encirclement-and-siege-attacks\" class=\"anchor\" id=\"responses-to-encirclement-and-siege-attacks\"\u003e\u003c/a\u003eResponses to Encirclement and Siege Attacks\u003c/h2\u003e\n\u003cp\u003eGoryeo’s defenders adjusted their defenses to the Mongols’ methods of attack. Siege warfare means fighting to attack and capture a fortress. The biography of Bak Seo in Goryeosa describes attacks ranging from assaults on the gates to attacks using ladders.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eMongol method of attack\u003c/th\u003e\n\u003cth\u003eGoryeo’s response as recorded\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Mongol method of attack\"\u003eAttacks on several gates\u003c/td\u003e\n\u003ctd data-label=\"Goryeo’s response as recorded\"\u003eDividing the defensive sectors and sometimes making sorties outside the fortress\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Mongol method of attack\"\u003eApproaching the base of the walls to dig tunnels\u003c/td\u003e\n\u003ctd data-label=\"Goryeo’s response as recorded\"\u003eBlocking equipment used to approach the walls\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Mongol method of attack\"\u003eAttacking the walls with pocha\u003c/td\u003e\n\u003ctd data-label=\"Goryeo’s response as recorded\"\u003eLaunching stones from pocha atop the walls in response\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Mongol method of attack\"\u003eAttacks using fire\u003c/td\u003e\n\u003ctd data-label=\"Goryeo’s response as recorded\"\u003eUsing water mixed with mud or stored water, depending on the form of attack\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Mongol method of attack\"\u003eApproaching with siege ladders called unje\u003c/td\u003e\n\u003ctd data-label=\"Goryeo’s response as recorded\"\u003eBlocking the ladders with daewupo fitted with large blades\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eHere, pocha refers to stone-throwing siege equipment. The name in the record cannot simply be equated with modern gunpowder cannons. Daewupo, too, is described in this record as a weapon fitted with a large blade. \u003ca href=\"https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040\"\u003eOriginal Text of the Biography of Bak Seo in Goryeosa and Commentary from Our History Net\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#how-wall-repairs-and-royal-orders-changed-the-course-of-the-battle\" class=\"anchor\" id=\"how-wall-repairs-and-royal-orders-changed-the-course-of-the-battle\"\u003e\u003c/a\u003eHow Wall Repairs and Royal Orders Changed the Course of the Battle\u003c/h2\u003e\n\u003cp\u003eThe key to sustaining the defense was immediately restoring collapsed sections of wall. Goryeosa describes repairs made whenever the walls were damaged. It also records that iron cables were used to reinforce them.\u003c/p\u003e\n\u003cp\u003eDamage to the walls did not immediately lead to the fall of the entire fortress. The defenders repaired damaged sections and prepared for the next attack. New History of Korea highlights the residents’ role in this repair work. \u003ca href=\"https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026amp;whereStr=\"\u003eNew History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”\u003c/a\u003e.\u003c/p\u003e\n\u003cp\u003eThe turning point that ended the fighting was a royal order sent from the court. Bak Seo had earlier rejected an appeal to surrender conveyed in a document from Wang Jeong, Duke of Hoean. The following year, Choe Rim-su and Min Hui delivered the royal order.\u003c/p\u003e\n\u003cblockquote\u003e\n\u003cp\u003eWe have already sent Jeong, Duke of Hoean, to make peace with the Mongol army, and our three armies have also surrendered. Stop fighting, come out, and surrender.\u003c/p\u003e\n\u003c/blockquote\u003e\n\u003cp\u003eGoryeosa, volume 103, “Biographies” 16, “Bak Seo”: Choe Rim-su and Min Hui’s appeal to surrender.\u003c/p\u003e\n\u003cp\u003eAfter repeated persuasion, Bak Seo surrendered under royal orders. The immediate reason the fighting ended must therefore be distinguished from the fortress falling through military action. These circumstances are recorded in the biography of Bak Seo in Goryeosa. \u003ca href=\"https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040\"\u003eOur History Net, “Bak Seo’s Battle at Gwiju Fortress”\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#the-battles-outcome-and-the-continuing-mongol-invasions\" class=\"anchor\" id=\"the-battles-outcome-and-the-continuing-mongol-invasions\"\u003e\u003c/a\u003eThe Battle’s Outcome and the Continuing Mongol Invasions\u003c/h2\u003e\n\u003cp\u003eGuju Fortress avoided capture, but its defense did not reverse the course of the war across Goryeo. Goryeo’s main army was defeated at the Battle of Anbuk-bu. When Mongol forces advanced toward Gaegyeong, the court sought peace.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eWhat is being assessed\u003c/th\u003e\n\u003cth\u003eConfirmed outcome\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"What is being assessed\"\u003eThe defense at Guju Fortress\u003c/td\u003e\n\u003ctd data-label=\"Confirmed outcome\"\u003eRepeated Mongol attacks were repelled\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"What is being assessed\"\u003eThe end of fighting at Guju Fortress\u003c/td\u003e\n\u003ctd data-label=\"Confirmed outcome\"\u003eSurrender under royal orders after the court negotiated peace\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"What is being assessed\"\u003eThe first Mongol invasion\u003c/td\u003e\n\u003ctd data-label=\"Confirmed outcome\"\u003eBrought to a close by the Mongol withdrawal in the first month of 1232\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"What is being assessed\"\u003eThe long war between Goryeo and the Mongols\u003c/td\u003e\n\u003ctd data-label=\"Confirmed outcome\"\u003eInvasions and resistance continued afterward\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eHere, ganghwa means an agreement to stop fighting. It is a different term from the Ganghwa in the relocation of the capital to Ganghwa Island that same year. Goryeo moved its capital to Ganghwa Island in 1232. A second Mongol invasion followed that year. \u003ca href=\"https://contents.history.go.kr/front/kc/printViewPopup.do?levelId=kc_i200800\"\u003eOur History Net, “The Mongol Invasions of Goryeo”\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#how-to-read-the-numbers-in-the-records\" class=\"anchor\" id=\"how-to-read-the-numbers-in-the-records\"\u003e\u003c/a\u003eHow to Read the Numbers in the Records\u003c/h2\u003e\n\u003cp\u003eNumbers relating to the Battle of Guju Fortress must be read with attention to what they count. Treating the size of a particular unit as the entire fortress garrison changes the meaning. The duration of one round of fighting must also be distinguished from that of the battle as a whole.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eFigure in the record\u003c/th\u003e\n\u003cth\u003eWhat the figure covers\u003c/th\u003e\n\u003cth\u003eCaution when interpreting it\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Figure in the record\"\u003e30 days\u003c/td\u003e\n\u003ctd data-label=\"What the figure covers\"\u003eOne round of siege fighting before the Mongols withdrew\u003c/td\u003e\n\u003ctd data-label=\"Caution when interpreting it\"\u003eNot the entire period, including later renewed attacks\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Figure in the record\"\u003eAbout 250 men\u003c/td\u003e\n\u003ctd data-label=\"What the figure covers\"\u003eSelect troops from the Protectorate, Wiju, and Taeju\u003c/td\u003e\n\u003ctd data-label=\"Caution when interpreting it\"\u003eNot the total number of defenders at Guju Fortress\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Figure in the record\"\u003e50 kan of wall\u003c/td\u003e\n\u003ctd data-label=\"What the figure covers\"\u003eA recorded section of wall destroyed during a renewed attack\u003c/td\u003e\n\u003ctd data-label=\"Caution when interpreting it\"\u003eThere is no basis for converting kan into an arbitrary number of meters\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eThese figures appear in the original text of Bak Seo’s biography in Goryeosa. The record also goes on to describe renewed attacks after the initial fighting. The beginning and end of the Battle of Guju Fortress therefore cannot be defined by the 30 days alone. \u003ca href=\"https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040\"\u003eOur History Net, Original Text of “Bak Seo’s Battle at Gwiju Fortress”\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#records-and-interpretations\" class=\"anchor\" id=\"records-and-interpretations\"\u003e\u003c/a\u003eRecords and Interpretations\u003c/h2\u003e\n\u003ch3\u003e\n\u003ca href=\"#what-is-directly-recorded\" class=\"anchor\" id=\"what-is-directly-recorded\"\u003e\u003c/a\u003eWhat Is Directly Recorded\u003c/h3\u003e\n\u003cp\u003eThe main historical source is Goryeosa, volume 103, “Biographies” 16, “Bak Seo.” It covers troop deployments, responses to siege attacks, wall repairs, and surrender under royal orders. It also describes the circumstances of Bak Seo’s retirement to his hometown after the battle.\u003c/p\u003e\n\u003cp\u003eIt also recounts a veteran Mongol commander’s praise for the defense. This should be read as an assessment included in Goryeosa. That statement alone cannot establish how this battle ranks against battles from other periods. \u003ca href=\"https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040\"\u003eOur History Net, “Bak Seo’s Battle at Gwiju Fortress”\u003c/a\u003e.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#assessments-shared-by-the-historical-commentaries\" class=\"anchor\" id=\"assessments-shared-by-the-historical-commentaries\"\u003e\u003c/a\u003eAssessments Shared by the Historical Commentaries\u003c/h3\u003e\n\u003cp\u003eThe commentaries consulted recognize the successful defense of Guju Fortress. New History of Korea discusses the participation of both regional troops and residents. “Bak Seo” on Our History Net distinguishes the military achievement from the subsequent surrender.\u003c/p\u003e\n\u003cp\u003eReading these accounts together also reveals the roles of people other than the commanders. Troops fighting in their assigned sectors and residents repairing the walls supported the defense. This explanation draws together the commentaries consulted; it is not a single view shared by all historians. \u003ca href=\"https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026amp;whereStr=\"\u003eNew History of Korea, “Victories at Gwiju Fortress and Jaju Fortress”\u003c/a\u003e, \u003ca href=\"https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110\"\u003eOur History Net, “Bak Seo”\u003c/a\u003e.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#what-remains-uncertain\" class=\"anchor\" id=\"what-remains-uncertain\"\u003e\u003c/a\u003eWhat Remains Uncertain\u003c/h3\u003e\n\u003cp\u003eThe commentaries differ in their accounts of Bak Seo’s activities after the war. New History of Korea states that he was later reappointed to office. “Bak Seo” on Our History Net considers the timing of his appointment as munha pyeongjangsa uncertain. It also leaves unresolved whether the appointment was made during his lifetime or awarded posthumously.\u003c/p\u003e\n\u003cp\u003eIt is therefore difficult to turn Bak Seo’s later life into a detailed chronology of his return to office. The records consulted also do not establish the total troop strength on either side. Nor is there any basis for adding accounts of Bak Seo’s feelings or speeches of encouragement absent from the records. \u003ca href=\"https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110\"\u003eOur History Net, “Bak Seo”\u003c/a\u003e.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#why-this-battle-is-studied-as-a-distinct-event-today\" class=\"anchor\" id=\"why-this-battle-is-studied-as-a-distinct-event-today\"\u003e\u003c/a\u003eWhy This Battle Is Studied as a Distinct Event Today\u003c/h2\u003e\n\u003cp\u003eThe Battle of Guju Fortress shows both local defense and national decisions about war. The successful defense of the fortress and the court’s decision to make peace were events at different levels. Both must be considered to understand the circumstances behind the eventual surrender.\u003c/p\u003e\n\u003cp\u003eThe records of wall repairs also draw attention to the work that sustained the fighting. This perspective considers the commanders’ actions alongside the residents’ roles. These are details lost when military history is reduced to victories, defeats, and the names of individuals.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#frequently-asked-questions\" class=\"anchor\" id=\"frequently-asked-questions\"\u003e\u003c/a\u003eFrequently Asked Questions\u003c/h2\u003e\n\u003ch3\u003e\n\u003ca href=\"#did-goryeo-win-the-battle-of-guju-fortress\" class=\"anchor\" id=\"did-goryeo-win-the-battle-of-guju-fortress\"\u003e\u003c/a\u003eDid Goryeo Win the Battle of Guju Fortress?\u003c/h3\u003e\n\u003cp\u003eThe defense succeeded in preventing the fortress from being captured. However, the defenders later surrendered under royal orders. The achievements of the local defense must be distinguished from the political conclusion.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#did-guju-fortress-refuse-to-surrender-to-the-end\" class=\"anchor\" id=\"did-guju-fortress-refuse-to-surrender-to-the-end\"\u003e\u003c/a\u003eDid Guju Fortress Refuse to Surrender to the End?\u003c/h3\u003e\n\u003cp\u003eIt did not give in to Mongol attacks or the initial appeals to surrender. However, it surrendered under royal orders in 1232. Any statement that it did not surrender needs to distinguish between these points in time.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#did-the-battle-last-only-30-days\" class=\"anchor\" id=\"did-the-battle-last-only-30-days\"\u003e\u003c/a\u003eDid the Battle Last Only 30 Days?\u003c/h3\u003e\n\u003cp\u003eThe 30 days refer to one round of siege fighting described in the record. The Mongols attacked again afterward. The full course of events must be considered from autumn 1231 to the first lunar month of 1232.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#what-roles-did-kim-gyeong-son-and-bak-seo-play\" class=\"anchor\" id=\"what-roles-did-kim-gyeong-son-and-bak-seo-play\"\u003e\u003c/a\u003eWhat Roles Did Kim Gyeong-son and Bak Seo Play?\u003c/h3\u003e\n\u003cp\u003eBak Seo commanded the troops gathered at Guju Fortress. Kim Gyeong-son’s unit was responsible for the southern side. Kim Jung-on’s unit defended the eastern and western sides.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#who-delivered-the-royal-order\" class=\"anchor\" id=\"who-delivered-the-royal-order\"\u003e\u003c/a\u003eWho Delivered the Royal Order?\u003c/h3\u003e\n\u003cp\u003eChoe Rim-su and Min Hui appear in the biography of Bak Seo in Goryeosa. They conveyed news of the court’s peace agreement and the surrender of the three armies. After repeated persuasion, Bak Seo obeyed the royal order.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#where-can-the-original-text-and-translation-be-found\" class=\"anchor\" id=\"where-can-the-original-text-and-translation-be-found\"\u003e\u003c/a\u003eWhere Can the Original Text and Translation Be Found?\u003c/h3\u003e\n\u003cp\u003eThey can be found in “Bak Seo’s Battle at Gwiju Fortress” on Our History Net. The page includes the original text of Bak Seo’s biography from Goryeosa. A translation and separate commentary are also provided.\u003c/p\u003e\n","tags":["History of Goryeo","Goryeo period"],"faqs":[{"question":"Are the Battle of Guju Fortress and the Battle of Gwiju the same battle?","answer":"They are different battles. The Battle of Guju Fortress was a defensive battle against Mongol forces in 1231. The Battle of Gwiju was a battle in which Gang Gam-chan and others defeated Khitan forces in 1019."},{"question":"Did Goryeo win the Battle of Guju Fortress?","answer":"The defense succeeded in preventing the fortress from falling to Mongol attacks. However, in 1232, the defenders surrendered following the court's peace agreement and royal orders. This cannot be described as a victory that ended the entire war against the Mongols."},{"question":"When did the Battle of Guju Fortress end?","answer":"The \"Bak Seo\" entry on Our History Net describes it as a surrender in the first month of 1232 under royal orders. The first month here refers to the lunar calendar used in the records of the time. It should not be arbitrarily converted to a solar calendar date."},{"question":"How did Bak Seo and Kim Gyeong-son divide responsibility for defending Guju Fortress?","answer":"Bak Seo commanded the assembled troops and coordinated the defense. Kim Gyeong-son's unit was responsible for the south. Kim Jung-on's unit defended the east and west."},{"question":"How did Guju Fortress hold out even after its walls collapsed?","answer":"The biography of Bak Seo in Goryeosa describes repeated repairs to the damaged fortress walls. It also records reinforcement using iron cables. New Edition of Korean History explains the residents' role in repairing the fortress walls."},{"question":"Did the Battle of Guju Fortress last only 30 days?","answer":"The 30 days refer to a record of one siege engagement. Mongol forces attacked again even after withdrawing. The duration of the entire battle should not be limited to 30 days."},{"question":"Did the defenders of Guju Fortress number only about 250 in total?","answer":"The figure of about 250 refers to the special troops from the protectorate, Wiju, and Taeju. It is not the total number of troops defending the entire fortress. It is difficult to determine the total troop strength from the records checked."},{"question":"Were the pocha mentioned in the Battle of Guju Fortress modern cannons?","answer":"The pocha in these records were stone-throwing siege engines. They cannot simply be regarded as the same weapons as modern gunpowder cannons. The daeupo is described as a weapon fitted with a large blade."},{"question":"Who were the royal envoys who urged Guju Fortress to surrender?","answer":"The biography of Bak Seo in Goryeosa names Choe Rim-su and Min Hui. The two announced the court's peace agreement and the surrender of the three armies. After repeated persuasion, Bak Seo surrendered under royal orders."},{"question":"Did the Mongol invasions end after the Battle of Guju Fortress?","answer":"The first Mongol invasion came to a close with the withdrawal in the first month of 1232. A second invasion followed that same year. The defense of Guju Fortress did not end the long war between Goryeo and the Mongols."},{"question":"What happened to Bak Seo after the battle?","answer":"Goryeosa states that he retired to his hometown following pressure from the Mongols. There is also a record that he later became munha pyeongjangsa. However, the \"Bak Seo\" entry on Our History Net does not establish when he was appointed or whether the appointment was made during his lifetime."},{"question":"What is the key primary source for the Battle of Guju Fortress?","answer":"The key primary source is the biography of Bak Seo in Goryeosa, volume 103, \"Biographies\" 16. The original text is available in \"Bak Seo's Battle at Gwiju Fortress\" on Our History Net. A translation and historical commentary are also provided."}],"sources":[{"url":"https://contents.history.go.kr/mobile/hm/view.do?levelId=hm_051_0040","title":"Our History Net, Korean History through Historical Sources, Bak Seo's Battle of Gwiju Fortress: Goryeosa, Volume 103, Biographies 16, Bak Seo, Original Text, Translation, and Commentary","type":"source"},{"url":"https://contents.history.go.kr/front/nh/print.do?levelId=nh_020_0030_0010_0030_0010_0020\u0026whereStr=","title":"Our History Net, New History of Korea, Victories at Gwiju Fortress and Jaju Fortress","type":"source"},{"url":"https://contents.history.go.kr/mobile/kc/view.do?levelId=kc_n202110","title":"Our History Net, Korean History Chronology, Bak Seo","type":"source"},{"url":"https://contents.history.go.kr/front/kc/printViewPopup.do?levelId=kc_i200800","title":"Our History Net, Korean History Chronology, The Mongol Invasions of Goryeo","type":"source"},{"url":"https://db.history.go.kr/id/ch_012_1019_02_00_0010","title":"Korean History Database, War Chronology, 1019, Lunar Month 2, Gang Gam-chan's Great Victory at Gwiju","type":"data_point"}],"images":[{"id":2580,"url":"https://injoys.com/rails/active_storage/blobs/proxy/eyJfcmFpbHMiOnsiZGF0YSI6Mzk4OTcsInB1ciI6ImJsb2JfaWQifX0=--a5875564dba3e1fbe360b5cf5117d5558c4a6e69/ai-1bec6427.webp","is_representative":false,"generation_method":"ai_semi","license":"ai_generated","mime_type":"image/webp","width":1536,"height":1024,"translations":{"ko":{"alt":"가을 구주성 안에서 사람들이 바구니로 돌을 나르고 나무 지지대를 댄 무너진 성벽을 보수하는 모습","caption":"고려군은 거듭된 보수로 몽골군의 반복 공격에 맞서 방어를 이어갔다.","description":null},"en":{"alt":"People carry baskets of stones and rebuild Guju Fortress’s damaged walls with timber supports in autumn.","caption":"Repeated repairs helped Goryeo sustain its defense against Mongol attacks at Guju Fortress.","description":null},"ja":{"alt":"秋の亀州城内で、人々が籠で石を運び、木の支えを組んだ崩れた城壁を修復している","caption":"高麗軍は修復を重ね、モンゴル軍の度重なる攻撃に対して防衛を続けた。","description":null},"es":{"alt":"Varias personas llevan cestas de piedras y reparan las murallas dañadas de Guju con apoyos de madera en otoño.","caption":"Las reparaciones reiteradas ayudaron a Goryeo a mantener la defensa de Guju ante los ataques mongoles.","description":null},"id":{"alt":"Orang-orang membawa batu dalam keranjang dan memperbaiki tembok Guju dengan penyangga kayu pada musim gugur.","caption":"Perbaikan berulang membantu pasukan Goryeo mempertahankan Guju dari serangan Mongol.","description":null},"pt":{"alt":"Pessoas carregam cestos de pedras e reparam as muralhas danificadas de Guju com apoios de madeira no outono.","caption":"Os reparos sucessivos ajudaram Goryeo a manter a defesa de Guju contra os ataques mongóis.","description":null},"zh-hant":{"alt":"秋日的龜州城內，人們用籃子搬運石塊，修補以木架支撐的破損城牆","caption":"高麗軍反覆修繕，持續抵禦蒙古軍接連發動的攻擊。","description":null},"de":{"alt":"Menschen tragen Steinkörbe und reparieren im Herbst Gujus beschädigte Mauern mit hölzernen Stützen.","caption":"Wiederholte Reparaturen halfen Goryeo, die Verteidigung Gujus gegen mongolische Angriffe aufrechtzuerhalten.","description":null}}},{"id":2581,"url":"https://injoys.com/rails/active_storage/blobs/proxy/eyJfcmFpbHMiOnsiZGF0YSI6Mzk5MDMsInB1ciI6ImJsb2JfaWQifX0=--519d4b6d6b27d5f35d9cab60c6b0119b42fb55ce/ai-1af49019.webp","is_representative":false,"generation_method":"ai_semi","license":"ai_generated","mime_type":"image/webp","width":1536,"height":1024,"translations":{"ko":{"alt":"눈 덮인 구주성의 보수된 성벽과 목조 성문 아래에서 수비군에게 두루마리를 내미는 사자","caption":"구주성은 함락을 막았지만, 조정의 강화 이후 1232년 왕명에 따라 항복했다.","description":null},"en":{"alt":"A messenger offers a scroll to defenders beneath Guju Fortress’s snowy gate, beside patched stone walls.","caption":"Guju Fortress resisted capture but submitted in 1232 by royal order after the court agreed to peace.","description":null},"ja":{"alt":"雪に覆われた亀州城の補修された石壁と木造の城門の下で、守備兵に巻物を差し出す使者","caption":"亀州城は陥落を免れたが、朝廷の講和後、1232年に王命に従って降伏した。","description":null},"es":{"alt":"Un mensajero ofrece un rollo a los defensores bajo la puerta nevada de Guju, junto a muros de piedra reparados.","caption":"Guju resistió la conquista, pero se rindió en 1232 por orden real tras el acuerdo de paz de la corte.","description":null},"id":{"alt":"Utusan menyodorkan gulungan kepada para pembela di bawah gerbang Guju yang bersalju, di sisi tembok yang ditambal.","caption":"Benteng Guju tidak berhasil direbut, tetapi menyerah pada 1232 atas perintah raja setelah istana menyepakati perdamaian.","description":null},"pt":{"alt":"Um mensageiro oferece um pergaminho aos defensores sob o portão nevado de Guju, junto a muralhas reparadas.","caption":"Guju resistiu à conquista, mas se rendeu em 1232 por ordem real após o acordo de paz da corte.","description":null},"zh-hant":{"alt":"覆雪的龜州城內，修補過的石牆旁，一名使者在木造城門下向守軍遞出卷軸","caption":"龜州城雖未被攻陷，仍在朝廷議和後於1232年奉王命投降。","description":null},"de":{"alt":"Ein Bote reicht Verteidigern unter Gujus verschneitem Tor neben ausgebesserten Steinmauern eine Schriftrolle.","caption":"Guju wurde nicht erobert, ergab sich aber 1232 nach dem Friedensschluss des Hofes auf königlichen Befehl.","description":null}}}],"published_at":"2026-11-08T18:32:55+09:00","updated_at":"2026-11-08T18:32:55+09:00","license":"cc_by","translation_status":"reviewed","available_locales":["ko","en","ja","es"],"data_locales":["ko","en","ja","es","id","pt","zh-hant","de"],"url":"https://injoys.com/en/articles/guju-fortress-battle-1231-mongol-siege-process-and-outcome"}