The Middle Kingdom begins with the reunification of Egypt under Mentuhotep II of Thebes, who defeated the rival Herakleopolitan line around 2055 BCE after the political division of the First Intermediate Period, and it is conventionally closed around 1650 BCE with the fragmentation of the Thirteenth Dynasty and the infiltration of the Hyksos into the eastern Delta. Amenemhat I, founder of the Twelfth Dynasty, relocated the royal residence north to Itjtawy near the Faiyum while leaving Thebes established as a major religious center, a dual focus that shaped Egyptian political geography for the rest of pharaonic history. Twelfth Dynasty kings undertook major land reclamation in the Faiyum, built a chain of fortresses to control Nubia and its gold, and left behind some of the most admired literature in the Egyptian language, including the Tale of Sinuhe and instructional texts written for royal and elite audiences.
The period is generally regarded by Egyptologists as a classical age of Egyptian language, art and administration, its literary and artistic standards used as later reference points, though its final century saw increasing rule by kings of shorter reigns and, by its end, growing Near Eastern settlement in the Delta that would produce the Hyksos rulers of the Second Intermediate Period. The Oxford History of Ancient Egypt situates the Middle Kingdom's stability against the more fragile decades that preceded and followed it.