Battle of Kōan

What Happened

In the summer of 1281, two Yuan fleets converged on northern Kyushu with orders to conquer Japan. The first ships of the southern force arrived on 16 July. By 12 August the two fleets had assembled and were ready to strike. On 15 August a major tempest struck the Tsushima Straits and lasted two full days, destroying most of the Yuan fleet.

Contemporary Japanese accounts put the number of ships destroyed in the storm at over 4,000. Around 80% of the Yuan soldiers either drowned or were killed by samurai on the beaches. The wreckage was so dense that, in one account, a person could walk across from one point of land to another on a mass of debris. The invaders who did reach the shore were repulsed shortly after landing.

The Japanese named the storm kamikaze (神風), "divine wind". The same word was later applied during the Second World War to pilots who carried out aerial suicide attacks.

Background

The Battle of Kōan was the second Mongol-led attempt to invade Japan, coming seven years after the first. That earlier attempt, the Battle of Bun'ei, had failed. The Kōan campaign was launched by the Yuan dynasty of China, with the Mongol Empire and Goryeo, the Korean kingdom, as participants. The Kamakura shogunate, which governed Japan during the Kamakura period (1185–1333), organised the defence.

The invasion force was divided into two armies, both large. They converged on the same target as before: northern Kyushu, the part of Japan closest to the Asian mainland and the obvious landing ground for any force crossing from Korea or China. The battle takes its name from the era in which it occurred, Kōan (弘安), year 4 of that era.

Why It Mattered

The failure of the second invasion ended the Mongol threat to Japan. Two massive expeditions, seven years apart, had both come to nothing, and the Yuan never attempted a third. The storm that broke the second fleet became the decisive event of the campaign in Japanese memory, and the word kamikaze entered the language as the name for a wind that saves the country.

The defence also shaped the politics of the Kamakura shogunate. The samurai who fought at Hakata Bay expected reward for their service, and the shogunate, facing the cost of a war with no conquered territory to distribute, struggled to meet those expectations. The strain contributed to the instability that marked the shogunate's final decades.

The Name in Japanese

The Japanese name is 弘安の役, read in kana as こうあんのえき, and romanised as Kōan no Eki. It means "the Kōan campaign" or "the Kōan war".

Breaking it down:

• 弘 — read here as こう (kō). It means "wide", "broad", or "vast". It is the first character of the era name Kōan.
• 安 — read here as あん (an). It means "peace", "calm", or "safe". Together, 弘安 (Kōan) is a nengō (年号), an era name, and this one ran from 1278 to 1288. Era names were chosen for their auspicious meaning, so Kōan carries the sense of "broad peace".
• の — read の (no). A possessive particle, it links the era name to the word that follows: "of Kōan".
• 役 — read here as えき (eki). It means "campaign", "war", "battle", or "service". In Japanese historical writing, 役 is the standard term for a military campaign, which is why both Mongol invasions carry it in their names.

So the full name is the era name plus の plus "campaign": the campaign that took place in the Kōan era. The same pattern gives the first invasion its name, 文永の役 (Bun'ei no Eki), after the Bun'ei era. Because both battles are named for eras rather than places, the alternative English name for this one — the Second Battle of Hakata Bay — is often clearer to readers who do not know the era names. Hakata Bay is the stretch of coast in northern Kyushu where the fighting took place.

Note that 弘安 is also read Kōan in the era-name system, and the era is the reason the battle is called what it is: the fighting fell in the fourth year of Kōan.

Key Figures

Kikuchi Takefusa (菊池武房) is recorded in connection with the conflict. He was a samurai of the Kikuchi clan, a Kyushu warrior house based in Higo province, and the defence of northern Kyushu fell heavily on clans such as his, who held lands on the island where the Yuan forces landed.

The Kamakura shogunate appears among the participants as the organising authority of the Japanese defence, and the Yuan dynasty, the Mongol Empire, and Goryeo appear as the invading side. The Yuan was the Mongol-led dynasty that ruled China and mounted both invasions; Goryeo, the Korean kingdom, provided ships, troops, and the crossing point for the northern arm of the fleet.