Imam Ali ibn Abi Talib is the first Imam of Shi'ite Muslims and the fourth Rightly Guided Caliph of the Sunni Muslims. He was born on Rajab 13, 23 BH (March 17, 599 AD) inside the Holy Kaaba in Mecca. His father was Abu Talib ibn Abdul-Muttalib, the chief of Banu Hashim at that time. Ali was Prophet Muhammad's cousin, as Abu Talib was the Prophet's paternal uncle. He was also the closest person to the Prophet from the time of his birth till the death of the Prophet. He is known as the most valiant warrior of his time, as he killed a number of famed warriors in battles with the Meccans. He is also known for his generosity, loyalty to the Prophet, justice, eloquence and wisdom. Many of his sermons and sayings have been collected in the form of a book called 'Nahjul Balagha (Peak of Eloquence)'.