http://en.wikipedia.org/wiki/Arab–Byzantine_wars
The
Arab–Byzantine wars were a series of wars between the mostly
Arab Muslims and the East Roman or
Byzantine Empire between the 7th and 11th centuries AD. Started during the initial
Muslim conquestsunder the expansionist
Rashidun and
Umayyad caliphs in the 7th century and continued by their successors until the mid-11th century.
The eruption of the Arabs from the
Arab Peninsula (now
Saudi Arabia) in the 630s resulted in the rapid loss of Byzantium's southern provinces (
Syria and
Egypt) to the Muslims. Over the next fifty years, under the aggressive Umayyad caliphs, the Muslims would launch repeated raids into still-Byzantine
Asia Minor, twice threaten the Byzantine capital,
Constantinople, with conquest, and outright conquer the Byzantine
Exarchate of Africa. The situation did not stabilize until after the failure of the
Second Arab Siege of Constantinople in 718, when the
Taurus Mountains on the eastern rim of Asia Minor became established as the mutual, heavily fortified and largely depopulated frontier. Under the
Abbasid Empire, relations became more normal, with embassies exchanged and even periods of truce, but conflict remained the norm, with almost annual raids and counter-raids, sponsored either by the Abbasid government or by local rulers, well into the 10th century.
During the first centuries, the Byzantines were usually in the defensive, and avoided open field battles, preferring to retreat to their fortified strongholds. Only after 740 did they begin to launch counterstrikes of their own, but still the
Abbasid Empire was able to retaliate with often massive and destructive invasions of Asia Minor. With the decline and fragmentation of the Abbasid state
after 861 and the concurrent strengthening of the Byzantine Empire under the
Macedonian dynasty, the tide gradually turned. Over a period of fifty years from ca. 920 to 976, the Byzantines finally broke through the Muslim defences and restored their control over northern Syria and Greater Armenia. The last century of the Arab–Byzantine wars was dominated by frontier conflicts with the
Fatimids in Syria, but the border remained stable until the appearance of a new people, the
Seljuk Turks, after 1060.
The Muslims also took to the sea, and from the 650s on, the entire
Mediterranean Sea became a battleground, with raids and counter-raids being launched against islands and the coastal settlements. Muslim raids reached a peak in the 9th and early 10th centuries, after their conquest of
Crete,
Malta and
Sicily, with their fleets reaching the coasts of France and Dalmatia and even the suburbs of Constantinople.