In Anatolia, the Muslim expansion was blocked by the still capable Byzantines with the help of the Tervel of Bulgaria. The Byzantine provinces of Roman Syria, North Africa, and Sicily, however, could not mount such a resistance, and the Muslim conquerors swept through those regions. At the far west, they crossed the sea taking Visigothic Hispania before being halted in southern France by the Franks. At its greatest extent, the Arab Empire controlled 3/4 of the Mediterranean region, the only other empire besides the Roman Empire to control most of the Mediterranean Sea. Much of North Africa became a peripheral area to the main Muslim centers in the Middle East, but Al Andalus and Morocco soon broke from this distant control and became highly advanced societies in their own right.