Rashidun Caliphate

The Rashidun Caliphate (Arabic: ٱلْخِلَافَةُ ٱلرَّاشِدَةُ, romanized: al-Khilāfah ar-Rāšidah) is a title given for the reigns of first caliphs (lit. "successors") — Abu Bakr, Umar, Uthman, and Ali collectively — believed to represent the perfect Islam and governance who led the Muslim community and polity from the death of the Islamic prophet Muhammad (in 632 AD), to the establishment of the Umayyad Caliphate (in 661 AD). The reign of these four caliphs is considered in Sunni Islam to have been "rightly-guided", meaning that it constitutes a model to be followed and emulated from a religious point of view. This term is not used by Shia Muslims, who reject the rule of the first three caliphs as illegitimate.

Following Muhammad's death in June 632, Muslim leaders debated who should succeed him. Unlike later caliphs, Rashidun were often chosen by some form of a small group of high-ranking companions of the Prophet in shūrā (lit. 'consultation') or appointed by their predecessor. Muhammad's close companion Abu Bakr (r. 632–634), of the Banu Taym clan, was elected the first caliph in Medina and began the conquest of the Arabian Peninsula. The only Rashidun not to die by assassination, he was succeeded by Umar (r. 634–644), his appointed successor from the Banu Adi clan. Under Umar, the caliphate expanded at an unprecedented rate, conquering more than two-thirds of the Byzantine Empire and nearly the entire Sasanian Empire.

After Umar's assassination, Uthman (r. 644–656), a member of the Umayyad clan, was chosen as caliph. He concluded the conquest of Persia in 651 and continued expeditions into the Byzantine territories. Uthman was assassinated in June 656 and succeeded by Ali (r. 656–661), a member of the Banu Hashim clan, who transferred the capital to Kufa. Ali presided over the civil war called the First Fitna as his suzerainty was unrecognized by Uthman's kinsman and Syria's governor Mu'awiya ibn Abu Sufyan (r. 661–680), who believed that Uthman's murderers should be punished immediately. Additionally, a third faction known as Kharijites, who were former supporters of Ali, rebelled against both Ali and Mu'awiya after refusing to accept the arbitration in the Battle of Siffin. The war led to the overthrow of the Rashidun Caliphate and the establishment of the Umayyad Caliphate in 661 by Mu'awiya.