King Gaeru (? ~ 166, r. 128 ~ 166) was the fourth king of Baekje, one of the Three Kingdoms of Korea. He founded Bukhan Mountain Fortress in present-day Goyang city, Gyeonggi in 132. Baekje fought off many Goguryeo invasions with this fortress later and King Chogo based his northward campaign on it.
Baekje-Silla relationship was peaceful for most of his period of reign. In 165, Gilseon (길선/吉宣), a minister of Silla, failed his coup d'etat attempt and fled to Baekje. King Gaeru gave him refuge and the two countries became hostile.
See also