Abu Bakr was not his real name. The Prophet (S) also gave him the title of 'Siddiq' - 'The Testifier to the Truth.'
Abu Bakr was a fairly wealthy merchant, and before he embraced Islam, was a respected citizen of Mecca. He was three years younger than Muhammad (peace be on him) and some natural affinity drew them together from earliest childhood. He remained the closest Companion of the Prophet all through the Prophet's life. When Muhammad (S) first invited his closest friends and relatives to Islam, Abu Bakr was among the earliest to accept it. He also persuaded Uthman and Bilal to accept Islam.
When the news came about Muhammad (S)'s Israa and Miraaj (the trip to Jerusalem and to the heavens) during the early days of Muhammad (S)'s prophethood, many dissenters came to Abu Bakr to ask him what he thought of the news. Abu Bakr had not heard of the news, but his reply showed his full dedication to Islam. Abu Bakr said (what means), "If Muhammad (S) said it, then I believe him."
In the early days of the Prophet's mission, when the handful of Muslims were subjected to relentless persecution and torture, Abu Bakr bore his full share of hardship. Finally when Allah's permission came to emigrate from Mecca, he was the one chosen by the Prophet (S) to accompany him on the dangerous journey to Madinah where he was with the Prophet (S) in the cave.
In the numerous battles which took place during the life of the Prophet (S), Abu Bakr was always by his side. Once, he brought all his belongings to the Prophet (S), who was raising money for the defense of Madinah. The Prophet asked "Abu Bakr (S), what did you leave for your family?" The reply came: "Allah and His Messenger."
Even before Islam, Abu Bakr was known to be a man of upright character and amiable and compassionate nature. All through his life he was sensitive to human suffering and kind to the poor and helpless. Even though he was wealthy, he lived very simply and spent his money for charity, for freeing slaves and for the cause of Islam. He often spent part of the night in supplication and prayer. He shared with his family a cheerful and affectionate home life.
Abu Bakr's children included 'Aisha, one of the wives of Prophet Muhammad (S), and Asma who gave birth to the first Muslim child in Madinah, 'Abdullah.
Such, then, was the man upon whom the burden of leadership fell at the most sensitive period in the history of the Muslims. As the news of the Prophet's death spread, a number of tribes rebelled and refused to pay Zakat (poor-due), saying that this was due only to the Prophet (peace be on him). At the same time a number of impostors claimed that the prophethood had passed to them after Muhammad and they raised the standard of revolt. To add to all this, two powerful empires, the Eastern Roman and the Persian, also threatened the new-born Islamic state at Madinah.
Under these circumstances, many Companions of the Prophet (S), including Umar, advised Abu Bakr to make concessions to the Zakat evaders, at least for a time. He disagreed and insisted that the Divine Law can not be divided, that there is no distinction between the obligations of Zakat and Salat (prayer), and that any compromise with the injunctions of Allah would eventually erode the foundations of Islam. Umar and others were quick to realize their error of judgment. The revolting tribes attacked Madinah but the Muslims were prepared. Abu Bakr himself led the charge, forcing them to retreat. He then made a relentless war on the false claimants to prophethood, most of whom submitted and again professed lslam.
The threat from the Roman Empire had actually arisen earlier, during the Prophet (S)'s lifetime. The Prophet (S) had organized an army under the command of Usama, the son of a freed slave. The army had not gone far when the Prophet (S) had fallen ill so they stopped. After the death of the Prophet (S) the question was raised whether the army should be sent again or should remain for the defence of Madinah. Again Abu Bakr showed a firm determination. He said, "I shall send Usama's army on its way as ordered by the Prophet (S), even if I am left alone."
The final instructions he gave to Usama prescribed a code of conduct in war which remains unsurpassed to this day. Part of his instructions to the Muslim army were:
"Do not be deserters, nor be guilty of disobedience. Do not kill an old man, a woman or a child. Do not injure date palms and do not cut down fruit trees. Do not slaughter any sheep or cows or camels except for food. You will encounter persons who spend their lives in monasteries. Leave them alone and do not molest them."
Khalid bin Waleed had been chosen by the Prophet (peace be on him) on several occasions to lead Muslim armies. A man of supreme courage and a born leader, his military genius came to full flower during the Caliphate of Abu Bakr. Throughout Abu Bakr's reign Khalid led his troops from one victory to another against the attacking Romans.
Another contribution of Abu Bakr to the cause of Islam was the collection and compilation of the verses of the Qur'an.
Abu Bakr died on 21 Jamadi-al Akhir, 13 A.H. (23 August 634 A.C.), at the age of sixty-three, and was buried by the side of the Prophet (peace be on him). His caliphate had been of a mere twenty-seven months duration. In this brief span, however, Abu Bakr had managed, by the Grace of God, to strengthen and consolidate his community and the state, and to secure the Muslims against the perils which had threatened their existence.