(c. 2686–2181 BC)
A term used by Egyptologists to refer to the stable period beginning in either Dynasty 3or Dynasty 4 to the end of Dynasty 6, which followed the Early Dynastic Period. It appeared that Egypt at the time had a highly organized autocratic government that could mobilize its resources and manpower in massive construction efforts, like the building of the pyramids. The period ended with the collapse of central authority possibly due to famine or increasingly powerful regional governors or nomarchs ushering in the First Intermediate Period.
See also Middle Kingdom; New Kingdom.
Historical Dictionary Of Ancient Egypt by Morris L. Bierbrier
Ancient Egypt. A Reference Guide. EdwART. 2011.