Bowl with stamped decoration Unified Silla Korean kingdom, period, 700 - 800 AD, Stoneware. Vessels became more uniform across the peninsula after Silla annexed Goryeo and Baekje and ruled considerable parts of the territory. In the Three Kingdoms period incised circular or triangular patterns were popular. This type of decoration was superseded by stamping from the late AD 500$ through to this early AD 800s.