Who was caliphs? Describe the expansion …

Caliphates wanted to capture the political power of prophet but no one could legitimately claim thain they will be the next ruler . The political authority was given to umma . The first caliph Abu bakr suppressed the revolts by campaigns. Second caliph umar shaped the policy of umma and given the policy of expansion of power. The third caliph Uthman wanted to capture central east asia. The calphs made a vast territory from river nile to oxus . But the army of iran and egypt combined and assassinated uthman. After uthman Ali became the fourth caliph . He faught his first war with Muhammad's wife aisha in the war of camel . He was not able to suppress Muawiya who was the kinsman of uthman and the governor of syria . He faught space his second war in siffin where his followers divided into two groups one where loyal to him and the second where the khurjis.Then one day ali went to a mosque in kufa and was assassinated by the kharjis.