三国史记
According to the "Samguk Sagi", the Goguryeo royal family claimed descent from the mythical emperor Gao Yang, who was the grandson of the Yellow Emperor of Chinese mythology, and thus took the surname of "Go" (高). However, this legend was discredited in the commentaries () of Kim Busik, the compiler of the "Samguk Sagi", who concluded that both Baekje and Goguryeo originated from Buyeo.