Sangju has played an important role in much of Korean history. It first emerges after the Silla conquest of the area, in which minor states such as Goryeong Gaya (in Hamchang-eup) and Sabeol-guk (in Sabeol-myeon) were subjugated. The dates at which these conquests occurred are open to dispute, but it is apparent that the area was under firm Silla control by 505, and probably for some time before then.