Historians have given the name "kingdom" to…

Historians have given the name "kingdom" to those periods in Egyptian history when the central government was strong, the country was unified, and there was an orderly succession of pharaohs.

At times, however, central authority breaks down, competing centers of power emerge, and the country is plunged into civil war or is occupied by foreigners.

These periods are known as "intermediate periods."

The Old Kingdom and the Middle Kingdom together represent an important single phase in Egyptian political and cultural development.

The Third Dynasty had reached a level of competence that marked a plateau of achievement for ancient Egypt.

After five centuries and following the end of the Sixth Dynasty (ca. 2181 BCE), the system faltered, and a century and a half of civil war, the First Intermediate Period ensued.

The reestablishment of a powerful central government during the Twelfth Dynasty, however, reinstitutes the patterns of the Old Kingdom.

Thus, the Old Kingdom and the Middle Kingdom may be considered together.