 Complete the following phrase:  Abu al-Muhajir Dinar, Uqbas successor, pushed westward into Algeria and eventually worked out a modus vivendi with Kusaila, the ruler of an extensive confederation of Christian Berbers. Kusaila, who had been based in Tlemcen, became a Muslim and moved his headquarters to Takirwan, near Al Qayrawan. This harmony was short-lived; Arabian and Berber forces controlled the region in turn until 697. Umayyad forces 