Following the death of the Prophet Muhammad in 632, Islam was lead by a series of four caliphs who had known the Prophet. These caliphs, known collectively by the Sunnis as the Four Rightly Guided Caliphs, led the Islamic world and greatly expanded its territory for the next 29 years.
Abu Bakr:
Abu Bakr was Muhammad’s father-in-law and served as one of his senior advisors. He was called Al-Siddiq (the truthful) by the Prophet as well as by later generations of Muslims.
Abu Bakr is mentioned in the Qur’an as the “second of the two who lay in the cave.” This was in reference to an event of hijra with the Prophet Muhammad where they hid in the cave in Jabal Thawr from the Meccan search party that had been sent after them. Abu Bakr was afraid that they would be found, but a spider spun a web over the cave entrance. The search party passed by the cave, assuming that it was unoccupied because of the spider’s web.
Abu Bakr was the first adult male to revert to Islam. He was a successful trader and he helped the nascent Muslim community financially.
After Muhammad became ill with his fatal illness, he said:
No doubt, I am indebted to Abu Bakr more than to anybody else regarding both his companionship and his wealth. And if I had to take a Khalil from my followers, I would certainly have taken Abu Bakr, but the fraternity of Islam is sufficient. Let no Door of the Mosque remain open, except the door of Abu Bakr.
Abu Bakr became the first caliph following Muhammad’s death. In his first address as caliph, he said:
I have been given the authority over you, and I am not the best of you. If I do well, help me; and if I do wrong, set me right. Sincere regard for truth is loyalty and disregard for truth is treachery. The weak amongst you shall be strong with me until I have secured his rights, if God wills; and the strong amongst you shall be weak with me until I have wrested from him the rights of others, if God wills. Obey me so long as I obey God and His Messenger. But if I disobey God and His Messenger, ye owe me no obedience. Arise for your prayer, God have mercy upon you.
As caliph, Abu Bakr defeated the rebellion of several Arab tribes (the Ridda Wars, or the Wars of Apostasy) and unified the entire Arabian peninsula. With stability in the area, he was able to launch successful campaigns against the Sassanid Empire (Persian Empire) and the East Roman Empire (Byzantine Empire) who had been threatening Arabia’s borders.
In response to the initial posting of this piece on Street Prophets, JDsg provided additional background:
The Ridda or Apostasy Wars were a series of conflicts with various Arab tribes that had become Muslim in the last years of Muhammad's (pbuh) life. These people thought that their agreement to become Muslim was a contract only with Muhammad (pbuh), and that once Muhammad (pbuh) was dead the contract was no longer valid. But Muslim thought has always been that becoming a Muslim is a lifetime commitment and, should a person's beliefs waver, it is the responsibility of the community to help the person back to a state of belief.
According to the Sunni Islam tradition, many Muslims who had memorized the Qur’an died in the Battle of Yamama, fought in 632. Umar ibn al-Khattab asked Caliph Abu Bakr to preserve the Qur’an so that it would not become corrupted. Subsequently, Abu Bakr appointed a committee headed by Zayd ibn Thabit to collect all of the Qur’anic verses. After the committee was satisfied that they had not missed any verses or made any mistakes in recording them, the text was written as a single manuscript and presented in a book form to Abu Bakr.
After only two years (27 months) as caliph, Abu Bakr died after an illness.
Umar ibn al-Khattab:
In 634, Umar ibn al-Khattab, the Commander of the Faithful, became the second caliph. He had been one of the chief advisors to Abu Bakr and had served as his secretary. Abu Bakr named Umar ibn al-Khattab as his successor because of his will power, intelligence, political astuteness, impartiality, justice, and care for poor and underprivileged people.
Umar ibn al-Khattab was a gifted orator and his addresses generally moved the people. He stressed the well being of the poor and underprivileged. Since the poor and underprivileged made up the bulk of the population, his popularity increased.
Many regard Umar ibn al-Khattab as one of the greatest political geniuses in history. He is often seen as the architect of the Islamic Empire. Under his leadership, the empire expanded and he undertook many administrative reforms. As a jurist, he began to codify Islamic law. He decreed that the Islamic calendar should be counted from the year of the Hijra of Muhammad from Mecca to Madinah.
In 644, Umar ibn al-Khattab was assassinated by a Persian in response to the Muslim conquest of Persia. On his death bed, he appointed a committee of six persons to select his successor.
Uthman ibn-Affian:
Uthman ibn Affian was converted to Islam by Abu Bakr. When Abu Bakr became caliph, Uthman ibn Affian was one of the first to offer his allegiance. He became a close advisor to the caliph and on his deathbed, Abu Bakr dictated his will to Uthman ibn Affian, naming Umar ibn al-Khattab as his successor. Uthman ibn Affian was the first to offer his allegiance to the new caliph. On the fourth day after the death of Caliph Umar ibn al-Khattab, Uthman ibn Affian was elected as the third caliph in 644.
As caliph, Uthman ibn Affian established the first Islamic naval force. He worked for the expansion of Islam and sent the first official Muslim envoy to China in 650. Although the envoy was unable to convert the Chinese emperor, he did obtain permission to proselytize in China and established the first Chinese mosque.
Caliph Uthman ibn Affian is best known for forming the committee which produced multiple copies of the Qur’an. Islam by this time had spread far beyond the Arabian Peninsula and there was some concern that different traditions would develop in some areas. It was important to develop a standardized text in order to eliminate regional variations.
Under the leadership of Caliph Uthman ibn Affian, the people prospered economically and they enjoyed a larger degree of political freedom. However, an anti-Uthman movement developed. Sunni and Shia scholars disagree as to the actual reasons for this movement. Egypt, Kufa, and Basra became independent from the caliph and became the centers of revolt.
A contingent of 1,000 people were sent from Egypt to Medina with instructions to assassinate Caliph Uthman and overthrow the government. Tempers flared, words were exchanged, and the pro- and anti-Uthman contingents pelted each other with stones. Uthman was hit and was carried into his house unconscious. The anti-Uthman forces stopped food and water from going into his house. The rebels broke into his house and assassinated him in 656.
Ali ibn Abu Talib:
Ali ibn Abu Talib, the cousin and son-in-law of the Prophet, became the Fourth Caliph in 656. According to Shia sources, he had been born in the Kaaba sanctuary in Mecca and was raised in the household of Muhammad. Muhammad told Ali that God had ordered him to give his daughter, Fatimah, to Ali in marriage.
Following the death of Muhammad, Ali withdrew from public affairs, devoting himself to his family and working as a farmer. He later became a trusted advisor to Caliph Umar ibn Khattab and served as the Chief Judge of Medina. He served on the council which selected the third caliph.
Following the assassination of Caliph Uthman, Ali was persuaded to become the fourth caliph. He was a profoundly religious man, dedicated to the cause of Islam and the rule of justice in accordance with the Qur’an. However, he assumed leadership at a time when the Islamic world was not unified. He was unwilling to compromise his principles for the sake of political expediency.
Caliph Ali ibn Abu Talib was murdered in 661, ending the period of rule by the four “rightly guided” caliphs.
Overview:
Sunni Muslims identify Abu Bakr and his three followers as the equally rightful successors to the Prophet and they celebrate them as the Rightly Guided Caliphs (Rashidun).
The Shiah Muslims regard Ali as the first in a line of infallible religious leaders called imams. They reject the authority of the first three caliphs. Ali is regarded by the Shiah Muslims as the first legitimate leader by virtue of his blood relationship with the Prophet and his status as Muhammad’s first convert to Islam.
This essay was originally posted on Street Prophets and has been updated thanks to the helpful comments from JDsg. His insights have helped in my understanding of Islam.