Final answer:
Around 3000 B.C.E., Upper and Lower Egypt were unified by a king named Narmer, who may also be known as Menes. This unification marked the beginning of the Early Dynastic Period and the flourishing of Egyptian culture and governance.
Step-by-step explanation:
Around 3000 B.C.E., a significant event in the political and cultural history of ancient Egypt occurred when Upper Egypt and Lower Egypt were unified into a single kingdom. This major achievement is commonly attributed to a king named Narmer. Over time, however, scholars have conflated Narmer with another king, Menes, leading to a belief that they may have been the same individual. Evidence from archaeology and records, such as the Predynastic Palette of Narmer, supports the assertion that Narmer of Upper Egypt was the one who achieved the unification by conquering Lower Egypt. This event marked the beginning of the Early Dynastic Period, characterized by the establishment of strong governance, the pharaoh system, and the foundation of Egyptian culture, which flourished remarkably throughout the Old Kingdom.
Upper Egypt, located in the southern part of the Nile valley, and Lower Egypt, situated in the northern delta region, had been politically distinct for centuries. The unification under Narmer's reign began a long line of pharaohs that would oversee Egypt's prosperity, cultural advancements, and the construction of monumental architecture such as the pyramids. The Egyptian state's population at the time of unification is estimated to have been as many as two million people, a significant size for the time period.