In ancient tribal times, Suwon was known as Mosu-guk (Korean : 모수국) of Mahan confederacy. During the Proto–Three Kingdoms period era, however, the area comprising modern Suwon and Hwaseong City was called Maehol-gun (매홀군). In 757, under King Gyeongdeok of the Unified Silla, the name was changed to Suseong-gun (수성군).