Battles & Wars › Gunpowder empires
Imjin War (Japanese invasions of Korea)
1592–1598· War· Asia & Pacific
Well documentedSolid records, physical evidence or scientific consensus.
Japan's ruler Toyotomi Hideyoshi invaded Korea twice, aiming at Ming China; Korean and Ming forces held them off until Japan withdrew in 1598.
See it on the Battles & Wars map →What happened
Hideyoshi, having unified Japan, landed about 150,000 troops at Busan in 1592, opening what Koreans call the Imjin War (임진왜란). Armed with matchlock muskets, they took Seoul in three weeks and Pyongyang soon after. Admiral Yi Sun-sin's navy cut their sea supply, Korean volunteer 'righteous armies' fought behind the lines, and Ming China sent armies. After failed peace talks Japan invaded again in 1597. Hideyoshi died in 1598, and his forces withdrew.
Why it matters
It devastated Korea, with deaths estimated in the hundreds of thousands or more, strained Ming China's finances, and left a lasting Korean memory of invasion.
How we know
Admiral Yi's war diary (Nanjung Ilgi), Ryu Seong-ryong's memoir Jingbirok, the Joseon court annals, Ming records, Japanese commanders' letters, and ruined Japanese-built castles on Korea's south coast.
Still debated
Hideyoshi's real goals (conquering China, keeping his warlords busy, or glory) and the true death toll are debated.
Inside this (2)
Connections (7)
▸Toyotomi Hideyoshi launched Imjin War (Japanese invasions of Korea)Well documented
The connection
Having unified Japan in 1590, Hideyoshi demanded that Korea's Joseon kingdom let his armies pass through to attack Ming China. When Korea refused, he sent about 158,000 troops across from Kyushu in 1592. After peace talks failed, he launched a second invasion in 1597. His death in 1598 led Japan's commanders to withdraw.
When and how
Planned from Nagoya Castle in Hizen, northern Kyushu, Hideyoshi's forward base; first landings at Busan in May 1592, second invasion in 1597.
How we know
Hideyoshi's letters to Korea and to his own commanders state his aim of conquering China; Korean, Chinese and Japanese records describe the invasions.
Debates and open questions
His motives are debated: real ambition to rule China, a need to keep his samurai busy and rewarded with land, or the vanity of an aging ruler.
▸Battle of Hansan Island cut Japan's sea supply in Imjin War (Japanese invasions of Korea)Well documented
The connection
Japan's plan relied on shipping troops and supplies around Korea's south and west coasts to its army at Pyongyang for the march into China. After Hansan, Hideyoshi ordered his admirals to avoid battle with Yi. Without sea supply, Konishi Yukinaga's army at Pyongyang stalled, giving Korean guerrillas and Ming armies time to counterattack in early 1593.
When and how
Korea's south coast, summer 1592; the Japanese army under Konishi Yukinaga waiting at Pyongyang; Hideyoshi directing the war from Japan.
How we know
Hideyoshi's orders forbidding his navy to engage survive, and Ryu Seong-ryong's Jingbirok links the naval defeats directly to Japan's stalled advance.
Debates and open questions
Some historians argue Japan's land advance would have stalled anyway from guerrilla attacks, winter and Ming intervention; Hansan's exact weight is debated.
▸Admiral Yi Sun-sin saved Korea at sea in Imjin War (Japanese invasions of Korea)Well documented
The connection
In 1592 Yi won every major sea battle, including Okpo, Sacheon, Hansan and Busan, keeping Jeolla Province and its rice harvest out of Japanese hands. In 1597, after his jailing and demotion, he was restored and won at Myeongnyang. He was killed at Noryang in December 1598, in the war's last great battle, as the Japanese withdrew.
When and how
Korea's southern seas, 1592–1598; Yi as Left Naval Commander of Jeolla Province, then supreme naval commander of the three southern provinces.
How we know
Yi's war diary, Nanjung Ilgi, now on UNESCO's Memory of the World register, his reports to the court, and the Annals of the Joseon Dynasty.
Debates and open questions
How decisive the navy was compared with Ming armies and Korean guerrillas is debated, and 'never lost a battle' depends on what counts as one.
▸Imjin War (Japanese invasions of Korea) foreshadowed Japan–China rivalry over Korea in First Sino-Japanese WarMostly agreed
The connection
In 1592–1598 Toyotomi Hideyoshi's armies invaded Korea, and Ming China sent armies to defend its tributary ally, fighting Japan on Korean soil. Three centuries later the pattern returned: a modernized Japan and Qing China both sent troops into Korea in 1894, and this time Japan won, ending China's claim to overlordship of Korea.
When and how
Korea, 1592–1598 (Hideyoshi, the Ming and Joseon) and again 1894–1895 (Meiji Japan and Qing China); the second war ended with the Treaty of Shimonoseki.
How sure are we?
Both wars are well documented. Treating 1592 as a precedent is historians' interpretation, though Meiji-era Japanese writers did celebrate Hideyoshi's Korean campaigns as forerunners.
Debates and open questions
How far the earlier war shaped Meiji thinking, versus Korea's plain strategic position, called 'a dagger pointed at the heart of Japan', is debated.
▸Battle of Myeongnyang stopped Japan's second invasion at sea in Imjin War (Japanese invasions of Korea)Mostly agreed
The connection
Japan's second invasion in 1597 aimed to seize Korea's southwest and send its fleet up the west coast to support the army. Myeongnyang blocked that sea route within weeks of Ming troops checking the land advance at Jiksan. The Japanese pulled back to forts on the south coast, and after Hideyoshi's death in 1598 they withdrew entirely.
When and how
Southwest Korea, autumn 1597; Yi's rebuilt fleet, Ming and Korean armies, and the Japanese forces of Hideyoshi's second invasion.
How sure are we?
Korean and Japanese records agree the Japanese navy turned back after Myeongnyang, and the ruins of their south-coast forts (waeseong) still stand.
Debates and open questions
Historians debate whether Myeongnyang, the land battle at Jiksan, or the coming winter did most to halt the second invasion.
▸Sengoku period (Japan's Warring States) forged the battle-hardened army that launched Imjin War (Japanese invasions of Korea)Well documented
The connection
A century of civil war gave Japan large, experienced armies with many thousands of matchlock guns and commanders skilled in siege warfare. Once Hideyoshi had unified the country, he turned these forces, and his restless daimyo, outward, landing about 150,000 men in Korea in 1592.
When and how
Japan, 1467–1590; invasion launched from Nagoya Castle in Kyushu, landing at Busan in May 1592.
How we know
Japanese muster rolls, Korean and Chinese records, and Jesuit letters from Japan describe the army's size and weapons.
Debates and open questions
Why Hideyoshi invaded is debated: ambition to conquer Ming China, a way to occupy and reward his daimyo, or control of trade.
▸Korean turtle ship (geobukseon) helped Korea win the sea war in the Imjin War (Japanese invasions of Korea)Mostly agreed
The connection
Turtle ships led the charge in several of Yi Sun-sin's 1592 victories, from Sacheon onward. With the panokseon fleet, they cut Japan's sea supply line along Korea's south coast, which stalled the Japanese advance beyond Pyongyang and gave Ming China time to intervene.
When and how
South coast of Korea, 1592–1598; Sacheon, Dangpo, Hansan Island and later battles.
How sure are we?
Yi's reports, his War Diary and the Annals of the Joseon Dynasty describe their role in battle.
Debates and open questions
Whether any turtle ships fought at Myeongnyang or Noryang is unclear; most were apparently lost at Chilcheollyang in 1597, while Yi was out of command.