High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! The Third Intermediate Period refers to the time in Ancient Egypt from the death of Pharaoh Ramesses XI in 1070 BC to the foundation of the Twenty-Sixth Dynasty by Psamtik I in 664 BC, following the expulsion of the Nubian rulers of the Twenty-Fifth Dynasty.This period is characterized by the country's fracturing kingship. Even in Ramesses XI' day, the Twentieth dynasty of Egypt was losing its grip on power in the city of Thebes, whose priests were becoming increasingly powerful. After his death, his successor Smendes I ruled from the city of Tanis, and the High Priests of Amun at Thebes ruling the south of the country in the period of the Twenty-first dynasty of Egypt. In fact, this division was less significant than it seems, since both priests and pharaohs came from the same family.