Islam burst forth from Arabia in the seventh century and spread with astonishing speed and force into the Middle East, Asia and northern Africa and the Mediterranean. While its success as a dominant culture has often been attributed to military strength, astute political organization, and religious factors, this Element focuses on the environmental conditions from which early Islamic societies sprang. In the belt of arid land that stretches from Iran to the Maghreb (Spain and Morocco)-i.e. the territories of early Islam-the adaptation of natural water systems, landforms and plant varieties was required to make the land habitable and productive.