ABSTRACT

In 1274, the Yuan dynasty under Kublai Khan launched its first major military expedition against Japan. The campaign, conventionally known in Japanese historiography as the Bun’ei no eki (文永の役), was the culmination of a decade of diplomatic negotiations, political pressure, military preparation, and the expansion of Yuan influence across East Asia.

Although commonly described as a Mongol invasion, the expedition was not an exclusively Mongolian military operation. It involved Mongol and Han Chinese troops, Goryeo Korean forces, sailors, navigators, and other personnel mobilized through the Yuan imperial system. Goryeo played a particularly important role in shipbuilding, provisioning, military recruitment, and maritime transportation.

This article reconstructs the 1274 campaign through a comparative examination of the Yuan Shi (元史), the Goryeosa (高麗史), Japanese historical records, and the illustrated Mōko Shūrai Ekotoba (蒙古襲来絵詞). It examines the strategic objectives of Kublai Khan, the organization of the expeditionary force, the attacks on Tsushima and Iki, the landing at Hakata Bay, the military encounter with Japanese defenders, and the circumstances surrounding the withdrawal.

The article argues that the first expedition should not be interpreted simply as either a failed conquest or a reconnaissance mission. Its outcome must be understood through the interaction of Yuan imperial strategy, Goryeo’s logistical obligations, the operational difficulties of maritime warfare, Japanese military resistance, and the limitations of the surviving historical evidence.

Keywords: Kublai Khan; Yuan dynasty; Mongol Empire; Goryeo; Japan; 1274 invasion; Tsushima; Iki; Hakata Bay; medieval maritime warfare.

1. INTRODUCTION: THE FIRST MILITARY ENCOUNTER

The 1274 expedition was one of the most significant military operations undertaken by Kublai Khan outside continental East Asia. Unlike the Mongol campaigns across the Eurasian landmass, the Japanese expedition required the movement of a large army across a maritime environment, the construction and mobilization of hundreds of vessels, and coordination among military forces from different political and cultural backgrounds.

The campaign took place during the Yuan dynasty’s consolidation of power in East Asia. Kublai Khan had proclaimed the dynastic name Great Yuan in 1271, while the conquest of the Southern Song remained unfinished. Japan, meanwhile, had not accepted the diplomatic demands communicated by the Mongol court.

The first invasion was therefore not an isolated military event. It emerged from a broader political situation involving the Yuan court, Goryeo, the Japanese imperial court, and the Kamakura shogunate.

The Japanese National Archives identifies the Yuan-Goryeo alliance as the military force behind the invasions of 1274 and 1281. Its historical collection also preserves documentary material relating to the diplomatic exchanges that preceded the campaign.

2. DIPLOMACY BEFORE WAR: 1266–1274

2.1 Kublai Khan’s diplomatic initiative

The military campaign of 1274 must be examined against the background of Yuan diplomatic activity beginning in 1266.

Kublai Khan sought to establish formal relations with Japan. His government sent diplomatic communications through Goryeo, whose geographical position made it an essential intermediary between the Mongol court and the Japanese archipelago.

The Japanese National Archives records that two diplomatic communications were issued in 1266: one instructed the Goryeo ruler to facilitate the Mongol mission to Japan, while the other addressed the Japanese ruler and proposed friendly relations. A Goryeo diplomatic mission carrying the letter reached Dazaifu in 1268.

The surviving diplomatic correspondence is historically important because it demonstrates that the Yuan court initially pursued communication through formal political channels.

However, the diplomatic language also contained an implicit threat. The Yuan court expected Japan to acknowledge its position within the emerging regional order. Refusal to establish relations could be interpreted as a political challenge to imperial authority.

2.2 Japan’s political response

Japan’s political structure complicates the interpretation of these diplomatic exchanges.

The Japanese emperor retained dynastic and ceremonial authority, while the Kamakura shogunate exercised the principal military and political power. Consequently, the Yuan demand addressed to the Japanese ruler encountered a political system in which authority was divided between the imperial court in Kyoto and the military government in Kamakura.

The refusal to respond to Yuan diplomatic demands was not simply a personal decision by the emperor. It reflected the political calculations of the Kamakura military government and the broader question of Japan’s relationship with the Yuan-led international order.

2.3 Why the diplomatic background matters

Lina Nie’s study, “Before the Storm: A Transrealm History of the Decades Leading Up to the First Mongol Invasion of Japan,” is especially valuable for understanding this period.

Published in Monumenta Nipponica 78, no. 2 (2023), the article examines the negotiations involving Kublai Khan, Chinese advisers, the Goryeo king, the Kamakura shogunate, and the Japanese imperial court. Its central contribution is to move beyond a narrowly military explanation and situate the invasion within a wider East Asian diplomatic and maritime history.

The 1274 invasion should therefore be understood as the military culmination of a prolonged diplomatic confrontation, rather than an entirely sudden attack.

3. GORYEO AND THE MILITARY PREPARATIONS OF 1274

One of the most important aspects of the first invasion was the role played by Goryeo.

Goryeo was not merely a geographical corridor through which the Yuan army passed. Its territory, population, shipbuilding resources, agricultural production, and maritime knowledge were essential to the expedition.

The Yuan court required the construction of ships, the recruitment of soldiers, the preparation of provisions, and the mobilization of sailors and navigators. These demands placed a considerable burden on Goryeo.

The Goryeosa records the arrival of 15,000 Yuan expeditionary troops in Goryeo on the fourteenth day of the fifth lunar month of 1274, corresponding to June 19 in the Gregorian calendar. It also records additional recruitment orders and instructions concerning agricultural production and military provisions.

These entries are significant because they show that the expedition required sustained administrative and economic mobilization before the fleet sailed.

3.1 Shipbuilding and naval preparation

According to the Korean historical synthesis published by the National Institute of Korean History, Goryeo mobilized approximately 30,000 people during the first half of 1274 and constructed a fleet of around 900 vessels, including 300 large ships.

The Yuan Shi, in its account of the Japanese expedition, also records an order to construct three categories of vessels:

• 300 qianliao vessels;

• 300 batulu light and fast vessels;

• 300 small water-supply vessels.

The combined fleet was therefore recorded as 900 ships. The same passage specifies 15,000 soldiers.

These vessel categories indicate that the expedition required more than a single type of transport ship. Different vessels served different operational requirements, including troop transport, movement, and the provision of water.

3.2 The economic burden on Goryeo

The construction of such a fleet required timber, labor, shipbuilding expertise, food supplies, and administrative coordination.

The expedition therefore had consequences beyond the battlefield. Goryeo’s population and institutions were required to support a military operation designed by the Yuan imperial government.

This is an important dimension of the campaign: the first invasion was not simply an army crossing the sea, but a large state-directed logistical undertaking.

4. THE EXPEDITIONARY ARMY: COMMANDERS, TROOPS, AND NUMBERS

The expedition was commanded by Yuan-appointed generals and supported by Goryeo military leadership.

The Goryeosa, in its account of the first invasion, identifies the principal commanders:

The Korean record gives the following force figures:

The combined personnel figure is approximately 39,700, excluding any uncertainty in the categories or the way the record counted supporting personnel.

4.1 A significant discrepancy between the historical records

A particularly important issue emerges when comparing the Yuan Shi and the Goryeosa.

The Yuan Shi, volume 208, records 15,000 soldiers and 900 ships. The Goryeosa, volume 28, gives a much larger figure: 25,000 Mongol and Han troops, 8,000 Goryeo troops, and 6,700 maritime personnel.

These numbers should not be combined as though they describe an identical administrative count. They may reflect different reporting purposes, categories, or stages of mobilization.

The discrepancy is itself historically important. It demonstrates why military figures in medieval chronicles must be compared rather than accepted uncritically.

For this article, the figures from the two records are retained separately. The Yuan Shi figure is treated as the Yuan court’s recorded expeditionary strength, while the Goryeosa provides a more detailed breakdown of the combined force.

4.2 The multinational character of the army

The expedition was Yuan-led, but its composition was broader than an ethnically Mongolian army.

The distinction between Mongol command authority and the ethnic or political origins of the troops is essential. Goryeo soldiers and maritime personnel were central to the operation, while Han Chinese troops formed part of the force recorded by the Korean chronicle.

This was an imperial military coalition mobilized through the political and administrative structures of the Yuan state.

5. THE INVASION OF TSUSHIMA

The first major target was Tsushima (對馬), an island located between the Korean Peninsula and Kyushu.

Its geographical position made it strategically important. Control of Tsushima could provide the expeditionary force with a forward position from which to continue toward Iki and the Japanese mainland.

The Japanese National Archives records that Yuan and Goryeo vessels appeared before Tsushima on October 5, 1274. The Korean historical account places the departure of the expedition from the Goryeo coast on October 3.

The defenders on Tsushima were considerably smaller than the invading force.

The Mōko Shūrai Ekotoba, associated with Takezaki Suenaga, depicts Japanese warriors fighting the invading army. Other Japanese accounts preserve the names of local military leaders, including Sō Sukekuni (宗助国), who was killed during the defense of the island.

The loss of Tsushima was not merely a local military defeat. It opened the next stage of the campaign and demonstrated the vulnerability of the islands located along the maritime approach to Kyushu.

The episode also raises an important question about the nature of the invasion: the Yuan force was not only attempting to defeat an opposing army, but also to secure a chain of maritime positions that would enable further movement.

6. THE ATTACK ON IKI ISLAND

Following Tsushima, the expedition moved toward Iki Island (壱岐).

The National Archives of Japan identifies October 14, 1274, as the date of the attack on Iki. The island’s position between Tsushima and northern Kyushu made it an important intermediate point in the invasion route.

The Goryeosa records that the expeditionary force killed more than one thousand Japanese defenders at Iki. It describes the invading army advancing along separate routes and the Japanese forces retreating under pressure.

The description is significant, but it must be interpreted in its source context. The Goryeosa was a Korean dynastic history compiled in the fifteenth century from earlier records. Its account reflects the political and historical perspective of Goryeo’s ruling institutions.

Nevertheless, it preserves valuable information about the military operations and the involvement of Goryeo commanders.

6.1 The strategic significance of Tsushima and Iki

The sequence of the campaign suggests a clear operational progression:

1. Secure the islands between Korea and Japan.

2. Remove or overcome local defensive resistance.

3. Advance toward northern Kyushu.

4. Establish a position near Hakata Bay.

The conquest of Tsushima and Iki enabled the Yuan force to approach the principal Japanese defensive zone on Kyushu.

The island engagements were therefore not incidental episodes. They formed the opening stage of the larger military operation.

7. THE LANDING AT HAKATA BAY

Hakata Bay, in northern Kyushu, was the principal strategic objective of the first expedition.

The area was important because it provided access to the Japanese mainland and lay close to Dazaifu, the administrative and military center responsible for Kyushu.

The Korean historical synthesis places the Yuan landing at Hakata on October 19, followed by fighting on October 20. The Japanese archival account gives the dates of the earlier island attacks but does not provide the same detailed sequence for the battle at Hakata.

Japanese warriors had been mobilized to defend the region. The resistance included forces from different provinces of Kyushu, operating under the military authorities of the Kamakura government.

7.1 The encounter between different military practices

The battle at Hakata brought different military practices into direct contact.

The Yuan-led force possessed coordinated formations, projectile weapons, and the capacity to employ signals and collective movements. Japanese warriors were experienced in mounted archery, close combat, and local military mobilization.

The Mōko Shūrai Ekotoba is especially important for examining the Japanese experience of this confrontation.

The scroll depicts Takezaki Suenaga and other warriors in combat. It provides visual evidence of armor, weapons, horses, and the conditions of battle, although it cannot be used as a complete record of the entire expedition.

The scroll is a warrior’s visual and textual testimony, not a neutral military report. Its purpose included recording Suenaga’s deeds and establishing his claims to recognition and reward. This context must inform any interpretation of its scenes.

7.2 The role of projectile weapons

The Yuan force’s use of bows and arrows was an important element of the fighting.

The expedition’s archers could attack defenders from a distance and support the movement of other troops. The historical record and visual tradition also associate the invading forces with explosive projectiles.

However, the evidence should be separated into distinct categories:

• Archery is documented as an important part of the invasion.

• Explosive projectiles appear in the visual tradition and are supported by archaeological evidence from the broader invasion period.

• The precise frequency, distribution, and battlefield effectiveness of these weapons during the 1274 campaign remain subjects requiring careful source comparison.

The existence of a weapon does not by itself establish how extensively it was used in a particular engagement.

8. THE WITHDRAWAL: MILITARY DAMAGE, WEATHER, AND STRATEGIC LIMITATIONS

The withdrawal of the Yuan force is one of the most debated aspects of the first invasion.

The Goryeosa provides a particularly important account. It records that after the fighting at Iki and the advance toward Hakata, a strong nighttime storm damaged the expeditionary fleet. Ships struck rocks and cliffs, and many were destroyed. The Goryeo commander Kim Sin (金侁) drowned.

The same historical tradition records that the expedition returned to Goryeo with substantial losses.

The National Institute of Korean History’s historical synthesis reports approximately 13,500 personnel who did not return. This is a figure from the Korean historical record and should not be treated as a modern independently verified casualty count.

8.1 Was the withdrawal caused only by a storm?

It would be too simplistic to explain the withdrawal entirely through the weather.

The Yuan force faced several interconnected difficulties:

• Resistance from Japanese defenders at Hakata.

• Damage and losses sustained during the campaign.

• The difficulty of maintaining a large army across a sea route.

• The need to protect and coordinate the fleet.

• Uncertainty about the ability to sustain further operations.

The Yuan Shi, volume 208, offers another important perspective. Its account states that the army was not properly organized and that its arrows had been exhausted, after which it returned following the seizure and plunder of surrounding areas.

This passage is particularly important because it does not present the withdrawal simply as the consequence of a storm.

It suggests operational and logistical problems within the expeditionary force itself.

The two historical records therefore provide complementary but not identical explanations:

• The Goryeosa emphasizes the storm and the destruction of ships.

• The Yuan Shi emphasizes disorder within the army and the exhaustion of arrows.

A convincing historical interpretation must consider both accounts rather than select only the explanation that best fits a later national narrative.

8.2 The question of a planned withdrawal

Some modern interpretations have suggested that the first expedition may have been intended as a limited operation rather than a full-scale attempt at permanent conquest.

Stephen Turnbull, in The Mongol Invasions of Japan, 1274 and 1281, discusses the possibility that the first expedition may have functioned partly as a reconnaissance in force.

This is a useful hypothesis, but it should not be presented as an established fact.

The Yuan court’s records describe a campaign intended to conquer Japan. The existence of an invasion order, the mobilization of a large fleet, and the deployment of a substantial army demonstrate that the operation was militarily serious.

Whether Kublai Khan expected the first expedition to achieve permanent conquest, force negotiations, test Japanese defenses, or accomplish several objectives simultaneously remains a question for further research.

9. THE HISTORICAL SIGNIFICANCE OF THE 1274 CAMPAIGN

The first invasion had consequences extending beyond its immediate military outcome.

9.1 For the Yuan dynasty

The expedition demonstrated the difficulty of extending continental imperial power across a maritime frontier.

The Yuan state could mobilize a large army and impose considerable demands on its subordinate territories, but the movement of forces across the sea created operational problems that differed fundamentally from land campaigns.

The campaign also exposed the limitations of an expeditionary force dependent on ships, provisions, and coordinated maritime transport.

9.2 For Goryeo

Goryeo bore a substantial burden.

The construction of ships, recruitment of soldiers, provision of sailors, and preparation of military supplies placed pressure on its economy and population.

The campaign also demonstrates the complexity of Goryeo’s position under Yuan authority. Its institutions were compelled to support the expedition, while Goryeo commanders and soldiers participated directly in the military operation.

9.3 For Japan

The invasion revealed the vulnerability of the islands and coastal regions of western Japan.

The Japanese government had to consider the possibility of another attack and strengthen its defensive preparations.

The experience of 1274 therefore became an important element in the military and political history of the Kamakura period.

9.4 For the history of East Asian warfare

The 1274 campaign should be studied as an international maritime conflict involving several political systems and military traditions.

It was neither simply a Mongolian land army crossing the sea nor an isolated confrontation between Mongols and samurai.

It was a Yuan-directed military expedition that depended heavily on Goryeo’s resources and involved the defense of Japan by the Kamakura military government.

10. CONCLUSION

The first Yuan expedition against Japan in 1274 was a complex military operation shaped by imperial strategy, diplomatic confrontation, multinational military organization, and maritime logistics.

The evidence from the Yuan Shi and the Goryeosa demonstrates that the campaign depended on the combined resources of the Yuan state and Goryeo. The attacks on Tsushima and Iki opened the route toward Hakata Bay, where the expeditionary force encountered Japanese resistance.

The withdrawal cannot be explained through a single cause. The Korean record emphasizes the destructive storm, while the Yuan account identifies disorganization and exhausted ammunition. Taken together, these records suggest that the expedition encountered both military and logistical difficulties.

The first invasion was therefore an important lesson in the limits of imperial military power when continental armies attempted to operate across a maritime frontier.

Most importantly, 1274 must be studied as an independent historical event. Its objectives, force composition, operational sequence, and withdrawal should not be confused with the much larger expedition of 1281.

The first campaign laid the foundation for the subsequent military preparations, political decisions, and historical memories that shaped the second invasion.

PRIMARY SOURCES

These are the most important sources for further examination of the 1274 campaign.

1. Yuan Shi (元史), Volume 208, “Foreign Countries: Japan” (列傳第九十五・日本).

The Yuan court history records the order to build 900 ships, the mobilization of 15,000 soldiers, the appointment of commanders, and the expedition’s operational difficulties.

• Original Chinese text and Korean translation – Northeast Asian History Foundation

• Yuan Shi, Volume 208 – comparative source database

2. Goryeosa (高麗史), Volume 28, “Annals of King Chungnyeol,” first year.

Particularly important for the composition of the expeditionary force, the names of Goryeo commanders, the fighting at Iki, the storm, and the losses suffered during the return.

• Historical source: Goryeosa account of the 1274 expedition

• Korean History Database – Goryeosa original records

3. Mōko Shūrai Ekotoba (蒙古襲来絵詞).

The illustrated testimony associated with Takezaki Suenaga. Essential for examining the Japanese warrior’s experience, armor, weapons, and battlefield representation.

• Princeton University – Annotated Mongol Invasion Scrolls

• Museum of the Imperial Collections – illustrated scroll collection

4. Japanese diplomatic documents and archival records.

– National Archives of Japan – Japan and Mongolia: A History of Exchanges

MODERN SCHOLARSHIP

1. Nie, Lina. “Before the Storm: A Transrealm History of the Decades Leading Up to the First Mongol Invasion of Japan.” Monumenta Nipponica 78, no. 2 (2023): 157–187.

Read the article

2. Turnbull, Stephen. The Mongol Invasions of Japan, 1274 and 1281. Oxford: Osprey Publishing, 2010.

Publisher preview and contents

3. Yamaguchi, Osamu. “Genkō or the Mongol Invasions of Japan: Especially on the Course of the Battles.” Tōyō Gakuho 43, no. 4 (1961): 521–558.

Repository record and abstract

4. Mizokawa, Koji. “Did ‘Kamikaze’ Blow in the Battle against Mongolians in the Year of Bun’ei 11 (1274)?” Hōsei Shigaku 60 (2003): 47–63.

Research article

5. Vitale, Judith. The Historical Writing of the Mongol Invasions in Japan. Harvard East Asian Monographs 474. Harvard University Asia Center, 2024.

Publication details

AUTHOR’S THESIS

The 1274 expedition should be understood as an attempt by the Yuan imperial state to extend its political and military influence across the maritime frontier of East Asia. Its failure to establish control over Japan was not simply the result of a storm or the resistance of the samurai. It reflected the difficulties of coordinating a multinational expeditionary force, sustaining an army across the sea, and translating continental imperial power into effective maritime control.

The campaign also reveals an important historical reality: Goryeo was not a peripheral participant but a central military and logistical component of the expedition.

Understanding the first invasion requires studying the Yuan imperial strategy, Goryeo’s contribution, and Japan’s defense as parts of one interconnected historical process.

Editorial and source-critical notes

Before treating this as a journal-submission version, three issues deserve further archival verification:

1. Force numbers: The 15,000 figure in the Yuan Shi and approximately 39,700 personnel in the Goryeosa are different source claims. They must remain distinct until their counting methods are examined.

2. Chronology: The dates in the Japanese and Korean records need to be checked against their original calendars. The dates above are presented according to the modern historical conversions used by the cited institutions.

3. The storm: The Yuan and Goryeo accounts offer different emphases. The weather’s exact contribution to the decision to withdraw should not be asserted beyond what the sources demonstrate.

This article is a separate study of 1274. The 1281 campaign will require its own article, rather than being folded into this narrative.

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