After Muhammad died (in 632 C.E.), the Muslim community needed a new leader. The divine revelations ended with the death of the Final Prophet, but the community still needed someone to have administrative responsibility. The Muslims needed a strong leader who would ensure that the community abided by the guidance of the Qur'an and the Prophet, establish justice, and create conditions whereby Islam could be fully practiced and implemented.

Muhammad did not name any particular individual to succeed him. He expected the community to select a new leader from among the most pious and well-suited of his companions. Muhammad's death sparked the debate over who was to take over leadership of the community.

Caliph Abu Bakr

During his final illness, Muhammad had appointed his close companion Abu Bakr to lead the community in prayer, and it was understood that Muhammad approved of him as future leader. Thus, after much discussion, the community elders elected Abu Bakr as the new leader. Abu Bakr had been a rather wealthy merchant in Mecca and was close to Muhammad in age. They grew up together, and he was always Muhammad's closest friend. He was among the first people to embrace Islam, back in the days when Muhammad was preaching to only his close friends and relatives. Abu Bakr had spent much of his life at Muhammad's side.

In his first address to the Muslim community following the election, Abu Bakr reportedly told the gathered crowd, “Oh people, I have been chosen by you as your leader, although I am no better than any one of you. If I do any good, give me your support. If I do any wrong, set me right…. Obey me as long as I obey God and His messenger. If I disobey God and His messenger, you are free to disobey me.” Abu Bakr helped to maintain the unity of the Muslim community during the potentially chaotic period after Muhammad's death.

After barely two years of leadership, Abu Bakr fell ill, and he died in 634 C.E. Before his death, he consulted with the senior companions of the Prophet, and Omar was chosen to succeed him as the next caliph of the growing Muslim state.

Caliph Omar

Omar had embraced Islam after initially denying and persecuting those who joined Muhammad in the early days. He was known to be very brave, bold, and straightforward. He was tough and disciplined and was well respected for always telling the truth. Despite his reputation for toughness, he was concerned for the welfare of all citizens, and he arbitrated disputes with justice and fairness.

During Omar's ten years in office, the borders of the Islamic state greatly expanded. Peace treaties were signed in Damascus and Jerusalem, offering complete security for all houses of worship and protecting the lives and property of Christian and Jewish citizens.

As the message of Islam spread, the Muslims defended themselves against aggression but did not use force to convert others to the faith. Rather, the people with whom the Muslims came into contact were inspired by their fairness and the simplicity of their faith. Many converted, and those who didn't were protected as minority communities within the Muslim state.

Omar was assassinated in 644 C.E. by a non-Muslim who had a grudge against him on a personal matter. Before his death, Omar had appointed a six-member committee to select his successor when the time came. After long deliberations, they elected Uthman to become the third caliph of Islam.

Caliph Uthman

Uthman was a close friend of Abu Bakr, and it was Abu Bakr who led him to Islam. Uthman was also a merchant, known for his generosity, integrity, and kindness. He was married to Muhammad's daughter, Ruqaiyah; when she passed away, he married another of Muhammad's daughters, Um Kulthum. He was known to be a simple man despite his wealth and was addressed as “Al-Ghani,” the generous man.

During his years of leadership, Uthman made great achievements in pushing the borders against the Persian and Byzantine empires and establishing Muslim rule in what is now Libya and parts of Eastern Europe. Uthman also led an effort to preserve the text of the Qur'an, and it remains in its original form today.

However, it was during Uthman's rule that the first cracks in Muslim unity began to appear. Muslim representatives from Egypt accused Uthman of favoritism toward his own family, the Umayyad clan. Uthman was murdered, and his killers were never fully prosecuted.

Following Uthman's death, the Prophet Muhammad's son-in-law, Ali, was chosen to be the next caliph. This reopened a conflict that eventually resulted in the only major division in the Muslim community, the rift between Sunni and Shi'a (or Shi'ite) Muslims.

According to the Shi'a Muslims, leadership of the community should have stayed within the Prophet Muhammad's own family from the very beginning and the appointment of Ali as caliph was long overdue. Others were not so supportive. One of Uthman's relatives, Mu'awiyah, was a powerful governor in Syria. He and others opposed the selection of Ali as the new leader. They were unhappy that Uthman's killers had not been brought to justice and believed that Ali had gained support from those who were responsible for the murder.

Caliph Ali

Ali was the young first cousin of Muhammad who grew up in his household and later married Muhammad's daughter, Fatima. Together they had two children, Hassan and Hussein. Ali was just a young boy when Muhammad began his mission, and thus Ali was one of the first in the family to embrace Islam. He had a deep knowledge of the Qur'an and was often consulted by the other caliphs for advice.

Ali took over the caliphate reluctantly and led the Muslim community from his base in Kufa, Iraq. Despite his desire to bring the community together, the conflict with Mu'awiyah continued to fester. The two sides battled in 657 C.E., and Ali began to lose strength even among his former supporters. He was killed in 661 C.E., and his son Hassan was proclaimed the next caliph. However, Hassan deferred to Mu'awiyah, who had already been accepted as caliph in many of the Muslim territories.

The first four caliphs of Islam — Abu Bakr, Omar, Uthman, and Ali — were among Muhammad's closest companions. They were pure-hearted and devout and held genuine concern for the health and welfare of the Muslim community. They are therefore known as the Rightly Guided Caliphs of Islam and are among the best examples for Muslims regarding fair and just leadership.