Modern name for ancient Nubt, Greek Ombos. A site in Upper Egypt north of Thebes where important remains from the late Predynastic Period were excavated by Flinders Petrie in 1895. The name is now used to denote the final phase of predynastic culture, divided into the periods Naqada I (c. 3900–3600 BC); Naqada II (c. 3600–3200 BC), which is best attested by its painted designs on pottery; and Naqada III (c. 3200–3100 BC), when the elements of kingship (Dynasty 0) and writing are first discernible.
Historical Dictionary Of Ancient Egypt by Morris L. Bierbrier
Ancient Egypt. A Reference Guide. EdwART. 2011.