El-Badari (Arabic: البداري) is an area of Upper Egypt between Matmar and Qau el-Kebir, including numerous Predynastic cemeteries (notably Mostagedda, Deir Tasa and the cemetery of el-Badari itself), as well as at least one early Predynastic settlement at Hammamia. The finds from el-Badari form the original basis for the Badarian period (c. 5500-4000 BC), the earliest phase of the Upper Egyptian Predynastic period. The el-Badari region, stretching for 30 km along the east bank of the Nile, was first investigated by Guy Brunton and Gertrude Caton-Thompson between 1922 and 1931. Most of the cemeteries in the Badarian region have yielded distinctive pottery vessels (particularly red-polished ware with blackened tops), as well as terracotta and ivory anthropomorphic figures, slate palettes, stone vases and flint tools. The contents of Predynastic cemeteries at el-Badari have been subjected to a number of statical analyses attempting to clarify the chronology and social history of the Badarian period.