[ALIGN=LEFT]Meaning of the Word 'Caliph' :
The word 'Caliph' is the English form of the Arabic word 'Khalifa,' which is short for Khalifatu Rasulil-lah.
The First Caliph, Abu Bakr " may Allah be pleased with him" , was not his real name. His real name was Abdul Ka'aba ('Slave of Ka'aba'), which Muhammad (peace be on him) later changed to Abdullah ('Slave of God'). The Prophet also gave him the title of 'Siddiq' - 'The Testifier to the Truth.'
The Second Caliph, Umar Bin Alkhtaab " may Allah be pleased with him ". The Prophet gave him the title 'Farooq' which means the 'Separator of Truth from False hood. Umar " may Allah be pleased with him " made no secret of his acceptance of Islam. He gathered the Muslims and offered prayers at the Ka'aba.
The Third Caliph, Uthman Bin Afaan " may Allah be pleased with him ". He lived very simply and slept on bare sand in the courtyard of the Prophet's mosque. he appointed a committee to collect the canonical verses and destroy the variant recensions. The result was the text that is accepted to this day throughout the Muslim world.
The Fourth Caliph, Ali ibn Abi Talib " may Allah be pleased with him ", Muhammad's cousin Ali was ten years old when the Divine Message came to Muhammad (peace be on him). Ali's humility, austerity, piety, deep knowledge of the Qur'an and his sagacity gave him great distinction among the Prophet's Companions. Abu Bakr, 'Umar and Uthman " may Allah be pleased with them " consulted him frequently during their caliphates.
I wrote briefly about them.... [/ALIGN]