At the beginning of the 21st Dynasty, Egypt had lost control of its empire and was weak and divided. The north was controlled by the Tanite 21st Dynasty (1075–950 BCE) and the southern Nile valley by the High Priest of Amun, who ruled from Thebes, home to the Amun cult. The Upper and Lower Kingdoms coexisted peacefully, possibly because the two dynasties shared the same family through intermarriage. There was a temporary period of reunification when the Theban King Psussennes ruled both kingdoms. However, it was not long before there was rebellion in Thebes and although quashed, it signalled the beginning of tensions between the two kingdoms. Meanwhile the Libyans, many of whom were already assimilated into the population, began to further penetrate the delta region. Amongst these were the Berber Chiefs of Libu, who later merged with the ‘Chiefs of the Ma(shuash)’ forming the 22nd Dynasty.