The Tasian culture is possibly the oldest-known Predynastic culture in Upper Egypt, which evolved around 4500 BC. It is named for the burials found at Deir Tasa, a site on the east bank of the Nile located between Asyut and Akhmim. The Tasian culture group is notable for producing the earliest blacktop-ware, a type of red and brown pottery, which has been painted black on its top and interior. This pottery is vital to the dating of the various predynastic Egyptian civilizations. Since all dates for the Predynastic period are tenuous at best, WMF Petrie developed a system called Sequence Dating by which the relative date, if not the absolute date, of any given Predynastic site can be ascertained by examining the handles on pottery.