Expansion. The territory of the earliest Muslim state, which modern historians call the khilafah for the period beginning in 632, expanded with startling rapidity. The ideological justification and proximate reason for this expansion was what the early Muslims understood as a divine imperative to claim the entire earth for God's rule (Qyr'an 9: 33; 48: 28; 61: 9). This military action continued with several interruptions for more than one hundred years until the beginning of the great Berber revolt against the Umayyads in 740, and it represents one of the greatest sustained military expansions in the history of the world, comparable in duration and extent with the territorial expansions of the Romans, the Mongols, the Spanish, the British, and the Americans. After 740, when the khilafah's sovereignty reached from Morocco to the borders of modern China, this expansion almost completely stopped, to be resumed only partially and intermittently by local...