Battle of Chilcheollyang

The Joseon fleet under Won Gyun was ambushed and almost wiped out at Chilcheollyang off Geoje; Won Gyun himself was killed.

When the Jeongyu War began, the Japanese used the double agent Yoshira to leak word that Kato Kiyomasa would be crossing the strait. Suspecting a trap, Yi Sun-sin did not sail; the court arrested him for disobedience and made Won Gyun Naval Commander of the Three Provinces. Under repeated pressure from Commander-in-Chief Gwon Yul, Won sortied and, with his crews exhausted, anchored at Chilcheollyang, where he was surprised at dawn on the 16th of the seventh month. Yi Eok-gi, Right Naval Commander of Jeolla, and others were killed; only Bae Seol, Right Naval Commander of Gyeongsang, escaped with 12 ships. The defeat opened Jeolla to the Japanese.