Saracen Conquests in the East
The first countries assailed were the Oriental possessions of the Byzantine Empire. In the reign of Abu-beker, Syria and Mesopotamia were subdued by Arabian armies. Under the next caliph, Omar, Egypt was conquered and Northern Africa overrun. The Arabs, or Saracens, as they were also called, met with comparatively little resistance in the Oriental countries, the countries beyond Mount Taurus; and this may be accounted for by the fact that these were the parts of the Roman Empire in which both Roman law and Christianity had taken least hold.
Thus the Eastern Empire was shorn of all its Oriental possessions; and even the farther East—Persia and the lands beyond, to India—was added to the Moslem dominion.