Ko Ŏnbaek

Ko Ŏnbaek (Korean: 고언백; Hanja: 高彦伯; 1545 – 1608) was a Korean military leader of the mid-Joseon period, noted for defending the royal tombs north of the capital during the Imjin War. Born in Kyodong into the Cheju Ko clan, he passed the military service examination and began service on the northern frontier, later holding commands and accompanying missions to Beijing.

With the outbreak of the Imjin War in 1592, he was assigned to the Pyongyang front, where he led a river crossing attack during the siege of the city. He was soon appointed magistrate of Yangju, where he raised local forces, fortified Buramsan Fortress to protect nearby royal tombs, and in 1593 ambushed and repelled a Japanese detachment north of Hansŏng in the Battle of Nowŏnp'yŏng.

Recognized for these achievements, Ko was promoted to Provincial Military Commander of Left Gyeongsang. From Gyeongju he coordinated with Ming generals in defending the region, repelling Japanese attacks, and later acted as intermediary in secret peace talks between Katō Kiyomasa and the monk-official Yujŏng at Sŏsaengp'o, while continuing to direct local raids and defensive operations.

During the Chŏngyu War he again held senior commands in Gyeongsang, joined the unsuccessful siege of Ulsan, and took part in later engagements. In 1604 he was made a Third-rank Sŏnmu Meritorious Subject and Prince of Chehŭng for his wartime service, but in 1608 he was implicated in Prince Imhae's treason case and executed by flogging after King Gwanghaegun's accession.