Goguryeo at its height, in 476 CE
An example of a Goguryeo tomb muralGoguryeo was founded in 37 BC by Jumong (posthumously titled as Dongmyeongseong, a royal given title).[44] Later, King Taejo centralized the government. Goguryeo was the first Korean kingdom to adopt Buddhism as the state religion in 372, in King Sosurim"s reign.[45][46]
Goguryeo reached its zenith in the 5th century, when King Gwanggaeto the Great and his son, King Jangsu, expanded the country into almost all of Manchuria and part of inner Mongolia, and took the present-day Seoul from Baekje. Gwanggaeto and Jangsu subdued Baekje and Silla during their times.[46]