In Ancient Egyptian history, dynasties are series of rulers sharing a common origin. They are usually, but not always, of the same family.
Ancient Egypt's historical period is traditionally divided into thirty-one pharaonic dynasties. The first thirty divisions are due to the 3rd century BC Egyptian priest Manetho, and appeared in his now-lost work Aegyptiaca, which was perhaps written for the Greek-speaking Ptolemaic Egyptian ruler of the time. The name of the short-lived thirty-first dynasty is a later coining.
While widely used and useful, the system does have its shortcomings. Some dynasties only ruled part of Egypt and existed concurrently with other dynasties based in other cities. The Seventh might not have existed at all, the Tenth seems to be a continuation of the Ninth, and there might have been one or several Upper Egyptian Dynasties before the First Dynasty.
This page lists articles on dynasties of Ancient Egypt. The cities in which power was held in each dynasty follow their names, in brackets.