The first four caliphs — the successors to the Islamic Prophet Muhammad — reigned from the years 632-661. The first caliph was Abu Bakr, followed by Umar, Uthman and Ali. The First Islamic Civil War took place during the reign of Ali and was fueled by controversy over the death of Uthman. The first four caliphs were supplanted by the Umayyad Dynasty.

The Ascension of Abu Bakr

Muhammad died in 632, leaving no clear successor. According to the Sahih Muslim collection of Muhammad's sayings, book 31 number 5920, Muhammad left behind "two weighty things" — the Quran and his family, especially his cousin and son-in-law, Ali. Supporters of Ali, who to this day are known as Shia Muslims, believe this meant Ali and his descendents were the rightful successors. Supporters of Abu Bakr, who are now known as Sunni Muslims, believe that the support of the early Muslim community granted Abu Bakr legitimacy. Abu Bakr's reign was short, ending in 634, but he set the precedent of the caliph being a first among equals, not a prophet.

The Caliphate of Umar and Uthman

Umar followed Abu Bakr as caliph. Although his reign was just 10 years, Umar oversaw the complete annihilation of the Sassanid Empire, expanding the caliphate from Persia to halfway across North Africa. Umar was assassinated by Persians in 644, and Uthman became caliph. Uthman would reign until 656, and his reign is best known for compiling a standardized version of the Quran. He was also known for the favoritism he showed in political appointments for his family, the Umayyads.

The Death of Uthman

In 656, Uthman was brutally assassinated in Medina by partisans who wanted the removal of an Egyptian governor. According to History Today, he was stoned until he was unconscious, stabbed to death and "his own treasured copy of the Koran was soaked with his blood." Upon Uthman's death, Ali finally became the caliph — the fourth and last of the Rightly-guided Caliphs. Ali did not punish Uthman's assassins, which strained tensions between himself and the Umayyads. This gave birth to the first Islamic Civil War.

The First Islamic Civil War

This war was fought between the supporters of Ali on one side, and the supporters of the Mu'awiyah and Umayyads on the other. Allies of note on each side included the Kharijites, a militant fundamentalist sect, on the side of Ali, and Aisha, the wife of Muhammad, on the side of the Umayyads. The first battle of the war was known as the Battle of the Camel, in 656, and the war lasted until Ali's death in 661.

The Death of Ali and the Beginning of the Umayyad Dynasty

Ali was assassinated by the Kharijites, his former allies, in 661. According to the University of Calgary, the Kharijites had intended to kill both Ali and Mu'awiyah and establish their own authority but could only kill Ali. Mu'awiyah made peace with Hasan, Ali's son, and began the Umayyad dynasty that would rule from 661-750. The Umayyad dynasty was a caliphate based on heredity rather than the spiritual merit of the four Rightly-guided Caliphs.