In a movie or novel, when the main story and events take place at an earlier time it is called a .

Historical Fiction. Or being specific about that moment in the movie or novel would be called a flashback.

Explanation:

fore the time of the First dynasty of Egypt (3100-2890 B.C.E.). Around 2500 B.C.E., Egyptians began moving south, and it is through them that most of our knowledge of Kush (Cush) comes. This expansion was halted by the fall of the Middle Kingdom of Egypt. About 1500 B.C.E. Egyptian expansion resumed, but this time encountered organized resistance. Historians are not sure whether this resistance came from multiple city states or a single unified empire, and debate over whether the notion of statehood was indigenous or borrowed from the Egyptians. The Egyptians prevailed, and the region became a colony of Egypt under the control of Thutmose I, whose army ruled from a number of sturdy fortresses. The region supplied Egypt with resources, especially gold. Although ruled by foreigners from about 1500 until about 780 B.C.E. the people of Kush prospered, enjoying internal and external peace. They greatly benefited from their physical location on important trade routes and appear to have taken full advantage of this by developing a commercial