The Moslem history of the Regency of Tunis may be conveniently divided into three epochs. The first is the period of Power, the second that of Piracy, and the third that of Decay. It was in A.D. 648 (the year of the Flight 26) that the Arabs, under Abd Allah Ben Saad, marched upon Gabes and Sbitela, then called Suffetula. The great Prefect Gregory raised an army of 120,000 men to oppose their advance, but on the plains of Akouba he lost both his life and his semi-independent dominions. Leaving the conquered province to the care of a chief named Djenaha, Abd Allah Ben Saad returned to Egypt. Sixteen years later Susa surrendered to the army of Abd Allah Ben Zobir, and six years afterwards Okba Ben Nafé el Fehri took Bizerta (properly called Ben Zert), and in A.D. 670 founded the city of Kairwán.[12] After carrying the arms of Islam to Fezzan and Morocco, Okba was slain ingloriously in the neighbourhood of Biscara. The oasis which surrounds his tomb bears the name of Sidi Okba to the present day. In A.D. 694 Hassan Ben el Noman destroyed Carthage, Tunis, and the neighbouring towns. Both Okba and Hassan were obliged to struggle against hostile movements of the indigenous Berbers. The annals of Tunis at this point merge for many years in those of Kairwán. Abd el Rahman Ben Habib founded in A.D. 745 the dynasty of the Abassides in the West, but half a century later they succumbed before the Aghlabites under the auspices of the Caliph Haroun el Rachid. Eleven princes succeeded Ibrahim Ben el Agheleb, the first of the line, and it was the Aghlabite sovereign Abou Muhamed Ziadat Allah who conquered Sicily, but in A.D. 909 they were overthrown in the revolution headed by Abou Abd Allah the Fathamite, who obtained the sway from Morocco to the district of Barca in Tripoli. The Obeïdite or Fathamite princes assumed the title of Caliph, and made Kairwán and the Mehdia successively the seat of their administration. In A.D. 972 the Caliph El Moëz conquered Egypt, and left the care of his dominions in Western Africa to his lieutenant Ebn Zeïri, who became independent, and transmitted his province to his descendants—the Zeïrites. This dynasty struggled successively with the Elmorabetin or Almoravides and the Almohades, who at length obtained supreme power over nearly all the North African littoral. Several powerful Berber clans seem to have waged war against the Almohades, and so far succeeded in weakening their power that, in A.D. 1228, one of their lieutenants, Abou Zakaria Yahya, son of Abou Muhamed Abd el Wahed _Ben Abou Hafs_, declared himself independent in Tunis, and founded the line of Hafsite sovereigns, who exercised supreme power in Tunis for a little more than three centuries.