During Geunchogo's reign, the territories of Baekje included most of the western Korean Peninsula (except the two Pyeongan provinces), and in 371, Baekje defeated Goguryeo at Pyongyang.
Under Geunchogo's regeringstid omfattede Baekjes områder det meste af den vestlige del af den Koreanske Halvø (undtagen de to Pyeongan provinser), og i 371 besejrede Baekje Goguryeo ved Pyongyang.