Database: Powers of a Caliph
The Abbasids' hold over their empire and much of the Muslim community came from their claiming of the title of caliph. The Arabic word from which it is derived, khalifa, means deputy and successor. In the context of leadership of the Islamic community, it meant the legal successor of the Prophet Muhammad.
Caliphs enjoyed vast political and military powers. They raised armies, levied taxes, nominated judges and administrators, and negotiated diplomatic agreements. But their authority was not boundless and they required the cooperation of local elites to ensure that their orders would be carried out.
Also, while the caliph’s power was theoretically sacrosanct, the democratic principle in Islam that upheld each individual's right to practice her or his faith meant that caliphal decisions could be challenged on the grounds that they did not obey God's law. And many were.