The Old Kingdom (2,778 - 2,065 BC) represents prosperity and gold age for the Egyptians. It is true, that just the Old Kingdom is the period of the biggest prosperity of Egyptian civilization from many points of view.
Djoser was the first Old Kingdom Pharaoh, who left tangible tracks after himself. This Pharaoh was the founder of the 3rd dynasty. There was no distinct break between this dynasty and the first two dynasty families and only in this dynasty begins the real history of Egyptian civilization. Fertile land was gradually systematically irrigated, a system of religious conceptions was initiated as well as the only language and writing and it came to realization of the land to all intents and purposes. Djoser's successors could use the knowledge gathered during centuries and create an original civilization.
3rd dynasty (2,778 - 2,723)
The most significant event of Pharaoh Djoser rule was undoubtedly the foundation of new capital Memphis (Mennefer), which replaced Thinis (near Abydos). Djoser also influenced the history, when he entrusted his vizier, inventive Imhotep, to build the Level pyramid in Saqqara. Djoser undertook good customs of his predecessors and continued in first Egyptian incursions into Nubia. We don't know almost anything about the Pharaohs, who came to the throne after Djoser. These rulers were Sekhemkhet, Khaba, Neferka and Huni.
4th dynasty (2,723 - 2,563)
Fourth dynasty is the best known dynasty in the whole Egypt history, because it is the dynasty of great pyramid builders. Sneferu was the first Pharaoh of this dynasty and incursion into Nubia, Libya and Sinai Peninsula were characteristic for his rule. He let build himself pyramids in Meidum and two others in Dahshur. His son Khufu is known for a large and wonderful pyramid with smooth walls, that he let build on a rock plain in Giza (recent suburb of Cairo) during 20 years.
Two different stems of royal family competed for succession after Khufu, but this opinion is already obsolete nowadays. Because of these fights Kuaba should have been murdered by his brother, the later ruler Djedefre. Djedefre was killed by Khafre then, who revenged his brother. Khafre was the builder of the great Sphinx in Giza. But according to recent theories Djedefre's brother died early but naturally. The dynasty rich in magnificent architectural constructions ends with the rule of Menkaure, who built the third pyramid in Giza and Shepseskaf.
5th dynasty (2,563 - 2,423)
Ra, the god of sun was worshipped in larger degree during this dynasty rule. Perhaps this god was chosen because the dynasty itself came also from Heliopolis. The importance of ruler's title "Son of Ra" was growing at that time. It was used in the previous dynasty for the first time and the king identified with the solar deity through it. The name of Ra became a part of rulers' native names in this dynasty. Number of Pharaohs made incursions into Sinai. It seems, that they were focused on Asia without forgetting about Nubia. The Old Kingdom was on the top of its fame at the end of this dynasty rule.
6th dynasty (2,423 - around 2,300)
The best known king of this dynasty is Pepi I. He let build a couple of temples, married a daughter of Abydos' high dignitary and he chose her sister as his second wife. He had sons with these two sisters, who undertook the rule after him. Pepi I. was interested in Nubia like his predecessors and made many incursions into Asia. His rule lasted almost 40 years. His son Merenre I ruled only for several years. Pepi I. follow up with his father's politics in Nubia and got far deep behind the first cataract, where he put Soudaneses under control.
Pepi II. was his half-brother and came to the throne after him. He was six at that time and ruled for incredible 94 years. It was the longest rule in the whole history of Egypt and the first business expeditions to Byblos (Phoenicia) and the Land of Punt came through just at that time. The monarch's title (it means the nome governor) became heritable. The decline of the Old Kingdom began with Pepi II. His high age and inability to rule strongly in a large kingdom meant the end of a unique prosperity.