This period covers all of ancient Egyptian prehistory, from the Paleolithic (Old Stone Age), down to the end of the Neolithic (New Stone Age). Strictly speaking, “prehistory” refers to the phase of a culture before it had writing. In Egypt’s case, writing appears at around the same time as the end of its Stone Age, around 3100 BC. This is also when Egypt as a unified political entity came into being, making it the world’s oldest nation state.
Before the formation of the first Egyptian state, during the Neolithic Period, an increasing homogenization of the different cultures that had emerged along the Nile Valley can be seen. Cultures are named after their sites of origin. Some of the most important of these are the Maadi Cultural Complex (c.4000–3100 BC) in Lower Egypt, near Cairo; Badarian culture (c.5500–4000 BC) near modern Asyut in Middle Egypt; and, most importantly Naqada I (c.4000–3500 BC) in Upper Egypt, near Luxor.
Naqada I culture, like its contemporaries, initially displays little in the way of social stratification, but this changes towards the end of this period. This trend became more pronounced during Naqada II (c.3500–3200 BC), which began to spread along the Nile Valley. Among the most important Naqada II sites, aside from Naqada itself, were Hierakonpolis (Kom al‑Ahmar), near Edfu, and Abydos, both in Upper Egypt. During Naqada III (c.3500–3100 BC), society continued to grow more complex, and differentiated itself from contemporary Nubian culture, eventually separating itself from it politically. The transition from Naqada III to the Early Dynastic Period was a smooth one. For this reason, Naqada III is sometimes also called “Dynasty 0”.
The powerful chiefs of this final period appear to have already been in control of most, if not all, of Egypt. Upper and Lower Egypt were geographically different, and the two had remained distinct until late in prehistory, and the ancient Egyptians never forgot this fact. Thus, when Egypt eventually became united as one political entity under a single ruler, the ancient Egyptians, throughout their entire history, referred to their king as the “Lord of the Two Lands”.