 Complete the following phrase:  From the 7th century onwards, as the Byzantines and neighbouring Sasanid Persians were severely weakened due to the protracted, centuries-lasting and frequent ByzantineSasanian wars, the Muslim Arabs began to make inroads into historically Roman territory, taking the Levant and North Africa and making inroads into Asia Minor. In the mid 7th century CE, following the Muslim conquest of Persia, Islam penetrated into the Caucasus region. Over the next centuries Muslim forces took Cyprus, Malta, Crete, Sicily and parts of southern Italy. Between 711 and 720, most of the lands of the Visigothic Kingdom of Iberia was brought under Muslim rule  save for small areas in the northwest Asturias and largely Basque regions in the Pyrenees. This territory, under the Arabic name Al-Andalus, became part of the expanding Umayyad Caliphate. The unsuccessful second siege of Constantinople 717 weakened the Umayyad dynasty and reduced their prestige. The Umayyads were then defeated by the Frankish leader Charles Martel at the 