Definition: Caliph (scroll down for answer)       Note: A Review of Islam can be found in the Religion Flashcards. Definition: Caliph A caliph was a religious leader who was also the head of the government. Starting in 632, Abu-Bakr, Umar, and Uthman all became the caliphs who succeeded Muhammad. They were able to take over the Arabian Peninsula in the Middle East. As they spread their power, they spread the religion of Islam as well. Click here for next flash card.      Back to eFlashcard headquarters