Battle of Hansan Island

In August 1592, off Hansan Island on the southern coast of Korea, Admiral Yi Sun-sin lured a large Japanese fleet out of a narrow strait into open water and destroyed most of it. Together with a follow-up attack at the harbour of Angolpo, the victory cost the Japanese dozens of ships and persuaded their leader, Toyotomi Hideyoshi, to halt naval operations along the Korean coast. It is remembered in Korea as one of the great naval victories of the Imjin War.

Hideyoshi, who had recently unified Japan, invaded Korea in May 1592 with the aim of going on to conquer Ming China. His armies landed at Busan and swept north, taking the capital, Hanseong, in June and Pyongyang in July. At sea the story was different. Korean warships, the sturdy panokseon, were heavier and carried more cannon than most Japanese vessels, and the Korean navy's few armoured "turtle ships" proved especially effective. Yi Sun-sin, a provincial naval commander based in Jeolla Province, won a series of victories in the summer of 1592 at Okpo, Sacheon, Dangpo and Danghangpo, sinking ships that carried Japanese troops and supplies.

Alarmed, Hideyoshi recalled three commanders from the land war, Wakisaka Yasuharu, Kuki Yoshitaka and Katō Yoshiaki, to deal with the Korean navy. Wakisaka, eager for glory, set out without waiting for the others. The Korean admirals Yi Sun-sin and Yi Ŏkki, joined by Wŏn Kyun, had gathered a combined fleet of some 53 to 56 warships. In mid-August, while anchored off Dangpo, they learned that Wakisaka's fleet, variously given as 73 or 82 vessels, had entered the narrow Gyeonnaeryang Strait between Geoje Island and the mainland.

The strait was too narrow and rocky for the Korean fleet to fight in. Yi Sun-sin therefore sent a handful of ships forward as bait. The Japanese took it, chasing them out into the open waters off Hansan Island. There the Korean fleet was waiting in a wide, U-shaped "crane wing" formation, with turtle ships and heavy warships at the centre and lighter vessels on the flanks. The Koreans closed around the pursuers and poured cannon fire into them, keeping enough distance to prevent the Japanese from using their preferred tactic of boarding. Incendiary bombs set Japanese decks ablaze.

The fighting lasted most of the day. Figures differ by source: one account puts Japanese losses at Hansan at 59 ships, 47 destroyed and 12 captured, while about 14 ships that had not engaged escaped. Wakisaka himself got away thanks to his fast flagship and withdrew to Gimhae. No Korean ships were reported lost; one count gives Korean casualties as 19 dead and 114 wounded.

Kuki and Katō then moved with 42 ships to the harbour of Angolpo, hoping to fight close to shore where the Koreans could not use their open-water tactics. When the Japanese would not be drawn out, Yi kept up a rolling bombardment of the anchored fleet for hours. Both Japanese commanders survived, and the crews escaped inland. Across the two engagements, roughly 100 Japanese ships are said to have been destroyed.

Hideyoshi responded by ordering his forces to stop all further naval operations. The Korean navy's control of the southern sea lanes made it far harder for Japan to supply and reinforce its armies by sea, and frustrated Japanese hopes of supplying a push towards China along the western sea route. Combined with Ming intervention and Korean guerrilla resistance on land, this contributed to the stalemate that eventually followed. Yi Sun-sin's campaign has since drawn admiring comparisons with the greatest admirals of European history, and the battle has been dramatised in Korean film and television.

Our 1600 map shows the Joseon kingdom of Korea shortly after the war, between Japan and Ming China.