When Omar, the second caliph, died by the dagger of a Persian slave, a council passed over the claims of Mohammed's son-in-law Ali to elect the Prophet's other son-in-law, Othman, an early convert from the aristocratic clan of the Omyyads.

As caliph Othman hoped to increase his authority by issuing an offical version of the Koran, and he established the rule of the Omayyads over the Islamic empire. This antagonized many other tribes and Othman was murdered by tribesmen from the garrisons of Iraq.

About the Koran complete guide and interpretation.