大约在公元前3150年，上下埃及的统一标志著古埃及早王朝时期的开始。早王朝时期包括了第一王朝与第二王朝，时间由前王朝时期直至公元前2686年，又或者直至古王国时期。在第一王朝时期，埃及的首都由阿拜多斯迁至孟斐斯，统治埃及的君主拥有神一般的权力，其统治范围由尼罗河三角洲至阿斯旺尼罗河第一瀑布。阿拜多斯仍然埃及南部宗教崇拜的中心。古埃及文明的许多成就，如艺术、建筑及宗教的各方面都在这段时期成形。
在上下埃及统一之前，埃及的各个城市都有自主权。在早王朝时期，以及后来的许多时间，埃及均被称为“两地”（Two Lands）。法老建立国家的行政及委任王室政府官员。中央政府的建筑是典型以木或砂岩建造的开放式神庙。埃及的国家组成基本上是本土的，上下埃及的人民的交谈很可能使用共同语，即埃及语，而各地则有方言，促成了国家的统一。而最早期的埃及象形文字于早王国时期之前出现，尽管我们无法透过那时的文字确定其口语。
根据曼涅托，第一位埃及的君主为美尼斯。但是，最早期有记录的第一王朝君主是荷尔-阿哈，以及第一位统一两地的君主那尔迈（前王朝时期的最后一位君主）——他的名字刻于一块古埃及人用作画眼线的磨板上，而后世称这块磨板为那尔迈石板。
农民的丧葬仪式与前王朝时期相同，但富有人家则要求更多。因此，埃及人开始兴建马斯塔巴，成为了古王国时期如阶梯金字塔的前身。谷类农业及中央化令埃及在接下来的800年都得到兴盛的发展。
The Archaic or Early Dynastic Period of Egypt immediately follows the unification of Lower and Upper Egypt c. 3100 BC. It is generally taken to include the First and Second Dynasties, lasting from the Protodynastic Period of Egypt until 2686 BC, or the beginning of the Old Kingdom. With the First Dynasty, the capital moved from Abydos to Memphis where an Egyptian god-king ruled a now unified polity that extended from the Nile Delta to the first cataract at Aswan. Abydos remained the major holy land in the south. The distinctive hallmarks of ancient Egyptian civilization, such as art, architecture and many aspects of religion, took shape during the Early Dynastic period.
Before the unification of Egypt, the land was settled with autonomous villages. With the early dynasties, and for much of Egypt's history thereafter, the country came to be known as the Two Lands. The rulers established a national administration and appointed royal governors. The buildings of the central government were typically open-air temples constructed of wood or sandstone. State formation in Egypt was primarily indigenous in character, and it is likely that a common language, namely Egyptian, was spoken in Upper and Lower Egypt in variant dialects, which facilitated the unification. The earliest hieroglyphs appear just before this period, though nothing is certain about the spoken language represented by the writing at the time.
According to Manetho, the first king was Menes. However, the earliest recorded king of the First Dynasty was Hor-Aha, and the first king to claim to have united the two lands was Narmer (the final king of the Protodynastic Period). His name is known because it is written on a votive palette used for grinding minerals for kohl, used by ancient Egyptians to outline the eyes. Funeral practices for the peasants would have been the same as in predynastic times, but the rich demanded something more. Thus, the Egyptians began construction of the mastabas which became models for the later Old Kingdom constructions such as the Step pyramid. Cereal agriculture and centralization contributed to the success of the state for the next 800 years.
It has also so been interpreted that King Menes and the whole traditional story of an Egypt unified under a single conquering ruler, who led his armies and conquered lower Egypt to establish the first dynasty in the lower Egyptian city of Memphis, is just mythology as are the twin kingdoms story. It seems certain that Egypt became unified as a cultural and economic domain long before its first king ascended to the throne in the lower Egyptian city of Memphis where the dynastic period did originate. Political unification proceeded gradually, perhaps over a period of a century or so as local districts established trading networks and the ability of their governments to organize agriculture labor on a larger scale increased, divine kingship may also have gained spiritual momentum as the cults of gods like Horus, Seth and Neith associated with living representatives became wide spread in the country.