Battle of Kōan

The Battle of Kōan (弘安の役, Kōan no eki), also known as the Second Battle of Hakata Bay, was the second attempt by the Mongol-led Yuan dynasty of China to invade Japan after their failed attempt seven years earlier at the Battle of Bun'ei. In the summer of 1281, the Yuan invaded with two large armies. The Japanese defenders were aided by a major storm which sank a sizeable portion of the Yuan fleets. The invaders who reached the shore were repulsed shortly after landing. The Japanese called the opportune storm kamikaze (lit. 'divine wind'), a name later used in the Second World War for pilots who carried out aerial suicide attacks.

Battle of Kōan
Part of the Mongol invasions of Japan
Japanese attack ships. Mōko Shūrai Ekotoba (蒙古襲来絵詞), circa 1293.
Date June 8 – August 22, 1281 Location Hakata Bay, near present-day Fukuoka, Kyūshū Result Japanese victory Invasion repulsed Destruction of the Mongol fleet
Belligerents
Kamakura Japan	Yuan dynasty Goryeo
Commanders and leaders
Hōjō Sanemasa [ja] Shōni Tsunesuke [ja] Ōtomo Yoriyasu [ja] Adachi Morimune [ja] Kōno Michiari [ja] Kikuchi Takefusa Takezaki Suenaga Shimazu Nagahisa	Atagai [zh] Fan Wenhu [zh] Hong Dagu Ala Temür [zh] † Li T'ing Kim Bang-gyeong
Strength
~40,000–60,000	~142,000 men 4,400 ships
Casualties and losses
Unknown	120,000+ ~20,000–30,000 South Chinese kept as Slaves (soon released)

Background

After the failed first invasion by the Yuan navy, the Japanese made many defense preparations, constructing numerous fortifications along the coast. Armies were kept in a state of readiness to repel a further attack.

In early 1280 Kublai Khan planned another invasion of Japan and ordered his shipbuilders to rebuild the whole fleet within a year. In the short time available many of the ships were poorly made; many were flat-bottomed river boats requisitioned by the Emperor.

Battle

By June 1281, 900 Yuan ships were gathered in Korea; the force was called the Eastern Route Army. They were crewed by 17,000 sailors, and transported 10,000 Korean soldiers and 15,000 Mongols and Chinese. The Southern Route Army, meanwhile, was assembled just south of the Yangtze River, in China. It is said to have consisted of 100,000 men on 3,500 ships. As before, Iki and Tsushima islands fell quickly to the much larger Yuan forces.

The Eastern Route Army arrived at Hakata Bay on June 23, and decided to proceed with the invasion without waiting for the larger Southern force which had still not left China. They were a short distance to the north and east of where their force had landed in 1274, and were in fact beyond the walls and defenses constructed by the Japanese. The samurai responded quickly, assaulting the invaders with waves of defenders, denying them the beachhead.

At night small boats carried small bands of samurai into the Yuan fleet in the bay. Under cover of darkness they boarded enemy ships, killed as many as they could, and withdrew before dawn. This harassing tactic led the Yuan forces to retreat to Tsushima, where they would wait for the Southern Route Army. However, over the course of the next several weeks, 3,000 men were killed in close quarters combat in the hot weather. Yuan forces never gained a beachhead.

The first of the Southern force ships arrived on July 16, and by August 12 the two fleets were ready to attack Japan. On August 15 a major tempest struck the Tsushima Straits, lasting two full days and destroying most of the Yuan fleet. Contemporary Japanese accounts indicate that over 4,000 ships were destroyed in the storm; 80% of the Yuan soldiers either drowned or were killed by samurai on the beaches. The loss of ships was so great that "a person could walk across from one point of land to another on a mass of wreckage".^[1]

Main battles of the Kōan Campaign

Battle of Tsushima Island – Japanese victory

On June 8, the Mongolian Army landed on Tsushima island and invaded. They met fierce resistance there and later withdrew.^[2]

Battle of Shika Island – Japanese victory

Japanese soldiers in Shika Island

On June 23, the Mongolians attempted a landing on Shika Island, but were unable to make significant advances. By June 24, Mongolian forces had control of most of the island, but on the morning of June 25, the Japanese army divided their force into two and attacked along Umi no Nakamichi.^[3] The Japanese army lost 300 soldiers but defeated Hong Dagu, who nearly died in this battle, and Zhang Cheng.^[4]

On June 26, Zhang Cheng solidified the defense of his army but the Mongolian army was again defeated by the fierce Japanese attacks.^[5] After this defeat the Mongolian army escaped to Iki Island.^[5]

Battle of Iki Island – Japanese victory

On July 16, a Japanese army of approximately 10,000, led by the Matsura clan, Ryūzōji clan and Takagi clan began an all-out attack on Iki Island.^[6] On July 18, Ryūzōji Iekiyo (龍造寺家清) landed on Setoura beach and defeated the Mongolian army. As a result, the Mongolian army abandoned Iki Island and withdrew to Hirado Island.^[7]

Battle of Mikuriya – annihilation of Mongol navy

Takezaki Suenaga attacking Yuan ships in Mikuriya

On August 20, Takezaki Suenaga attacked and annihilated the Mongolian Navy.^[8] After this battle, most of the commanders of the Mongolian army escaped to their own country.^[9]

Battle of Taka Island – annihilation of Mongol army

Fierce battle in Taka Island

On August 22, there were about 100,000 soldiers of the Mongol army without commanders.^{[9][10][11][12]} Upon realizing this situation, the Japanese army launched an attack. Togō Korechika (都甲惟親), Togō Koretō (都甲惟遠), Fujiwara no Sukekado (藤原資門) and Shimazu Nagahisa (島津長久) annihilated the remaining Mongolian army and took 20,000 to 30,000 prisoners in this battle.^[9] At the completion of this battle, Japan's victory was confirmed.

Aftermath

Kublai Khan began to gather forces to prepare for a third invasion attempt, but was soon distracted by events in Southeast and Central Asia,^{[citation needed]} and no third attempt was ever made.

See also

• Battle of Bun'ei - the first invasion attempt by Kublai Khan, in 1274.
• Mongol invasions of Japan

Notes

1. Winters, pp. 14–15
2. 『高麗史』 巻一百四 列伝十七 金方慶「方慶與忻都茶丘朴球金周鼎等發、至日本世界村大明浦」
3. 『高麗史節要』巻二十 十四葉 忠烈王七年六月壬申（八日）「六月壬申（八日）、金方慶金周鼎朴球朴之亮荊萬戶等、與日本兵力戰、斬首三百餘級、官軍潰、茶丘乗馬走、王萬戸復横撃之、斬五十餘級、日本兵之退、茶丘僅免、翼日復戰敗績、」
4. 『高麗史』巻一百四 列伝十七 金方慶「六月、方慶周鼎球之亮荊萬戸等、與日本兵合戰、斬三百餘級、日本兵突進、官軍潰、茶丘棄馬走、王萬戸復横撃之、斬五十餘級、日本兵之退、茶丘僅免、翼日復戰敗績、」
5. 『元敦武校尉管軍上百戸張成墓碑銘』「（至元）十八年、樞密院檄君、仍管新附□□（軍百？）率所統、?千戸岳公琇、往征倭、四月□（發？）合浦登海州、以六月六日至倭之志賀島、夜将半、賊兵□□來襲、君與所部據艦戦、至暁、賊船廻退、八日、賊遵陸復來、君率纏弓弩、先登岸迎敵、奪占其□要、賊弗能前、日?、賊軍復集、又返敗之、明日、倭大會兵來戦、君統所部、入陣奮戦、賊不能□（支？）殺傷過□（當？）賊敗去。」
6. 『歴代鎮西要略』
7. 『元史』巻一百五十四　列傳第四十一 洪福源・附洪俊奇「十七年、授龍虎衞上將軍、征東行省右丞、十八年、與右丞欣都、將舟師四萬、由高麗金州合浦以進、時右丞范文虎等、將兵十萬、由慶元、定海等処渡海、期至日本一岐、平戸等島合兵登岸、兵未交、秋八月、風壞舟而還。」
8. 『肥前武雄神社文書』黒尾社大宮司藤原経門申状「肥前国御家人黒尾社大宮司藤原資門謹言上　欲早且依合戦忠節、且任傍例、預勲功賞去弘安四年遺賊合戦事、右、遺賊襲来之時、於千崎息乗移于賊船、資門乍被疵、生虜一人分取一人了、将又攻上鷹嶋棟原、致合戦忠之刻、生慮二人了、此等子細、於鎮西談議所、被経其沙汰、相尋証人等、被注進之処、相漏平均恩賞之条、愁吟之至、何事如之哉、且如傍例者、到越訴之輩、面々蒙其賞了、且資門自身被疵之条、宰府注進分明也、争可相漏平均軍賞哉、如承及者、防戦警固之輩、皆以蒙軍賞了、何自身手負資門不預忠賞、空送年月之条、尤可有御哀憐哉、所詮於所々戦場、或自身被疵、或分取生慮之条、証人等状?宰府注進分明之上者、依合戦忠節、任傍例欲預平均軍賞、仍恐々言上如件、永仁四年八月 日」
9. 『元史』巻二百八 列傳第九十五 外夷一 日本國「（至元十八年）官軍六月入海、七月至平壷島（平戸島）、移五龍山（鷹島か）、八月一日、風破舟、五日、文虎等諸將各自擇堅好船乘之、棄士卒十餘萬于山下、衆議推張百戸者爲主帥、號之曰張總管、聽其約束、方伐木作舟欲還、七日日本人來戰、盡死、餘二三萬爲其虜去、九日、至八角島、盡殺蒙古、高麗、漢人、謂新附軍爲唐人、不殺而奴之、閶輩是也、蓋行省官議事不相下、故皆棄軍歸、久之、莫靑與呉萬五者亦逃還、十萬之衆得還者三人耳。」
10. 『薩摩比志島文書』比志島時範軍忠状案「次月七月七日鷹嶋合戦之時、自陸地馳向事、爰時範依合戦之忠勤、爲預御裁許、粗言上如件、弘安五年二月 日」
11. 『薩摩比志島文書』島津長久證状「同閏七月七日鷹嶋合戦之時、五郎次郎自陸地馳向候之条、令見知候了、若此條僞申候者、日本國中大少神罸可罷蒙長久之身候、恐惶謹言、弘安五年四月十五日　大炊助長久」
12. 『江上系図』「西牟田彌次郎永家。弘安四年。大元大將督六万艘十万人。寇鎭西。此時永家戰于松浦之鷹島抽功。於是爲之賞。肥前國神崎郡中數箇。」

References

• Davis, Paul K. (1999). 100 Decisive Battles: From Ancient Times to the Present. Oxford: Oxford University Press. ISBN 978-0-19-514366-9; OCLC 45102987
• Titsingh, Isaac. (1834). Nihon Odai Ichiran; ou, Annales des empereurs du Japon. Paris: Royal Asiatic Society, Oriental Translation Fund of Great Britain and Ireland. OCLC 5850691
• Turnbull, Stephen R. (2003). Genghis Khan and the Mongol Conquests, 1190-1400. London: Taylor & Francis. ISBN 978-0-415-96862-1
• Davis, Paul K. (2001), 100 Decisive Battles: From Ancient Times to the Present, Oxford: Oxford University Press, ISBN 0-19-514366-3
• Winters, Harold A.; Galloway, Gerald E. Jr.; Reynolds, William J.; David W. Rhyne (2001-03-09). Battling the Elements: Weather and Terrain in the Conduct of War. JHU Press. ISBN 978-0-8018-6648-7. Retrieved 11 August 2011.

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