Jamieson, Fausset and Brown on Genesis 12:14

14. when Abram was come into Egypt--It appears from the monuments of that country that at the time of Abram's visit a monarchy had existed for several centuries. The seat of government was in the Delta, the most northern part of the country, the very quarter in which Abram must have arrived. They were a race of shepherd-kings, in close alliance with the people of Canaan.