Sayyid Ruhollah Mūsavi Khomeini, 24 September 1902 – 3 June 1989), known in the Western world as Ayatollah Khomeini, was an Iranian Shia Muslim religious leader, philosopher, revolutionary and politician. He was the founder of the Islamic Republic of Iran and the leader of the 1979 Iranian Revolution that saw the overthrow of the Pahlavi monarchy and Mohammad Reza Pahlavi, the Shah of Iran. Following the revolution, Khomeini became the country's Supreme Leader, a position created in the constitution of the Islamic Republic as the highest-ranking political and religious authority of the nation, which he held until his death. On 1 February 1979 Ayatollah Ruhollah Khomeini, returned to Iran after 14 years in political exile. Khomeini had been a prominent opponent of Mohammad Reza Shah Pahlavi, who had fled the country during the events of the Iranian Revolution. Upon his return, he was greeted by crowds of millions, and within 10 days the revolution would be successful. Khomeini's return and the 10 days following are now celebrated in Iran as the Fajr decade.
At the age of 61, Khomeini found the arena of leadership open following the deaths of Ayatollah Sayyed Husayn Borujerdi (1961), the leading, although quiescent, Shi'ah religious leader; and Ayatollah Abol-Ghasem Kashani (1962), an activist cleric. The clerical class had been on the defensive ever since the 1920s when the secular, anti-clerical modernizer Reza Shah Pahlavi rose to power. Reza's son Mohammad Reza Shah, instituted a "White Revolution", which was a further challenge to the Ulama. Imam Khomeini was arrested and was exiled from Iran for opposing the king's cruel actions(Iran's ruling system). Khomeini was a marja ("source of emulation") in Twelver Shia Islam, a Mujtahid or faqih but he is primarily known for his political activities. He spent more than 15 years in exile for his opposition to the last Shah. mostly in the holy Shia city of Najaf, Iraq. At first he was sent to Bursa,Turkey on 4 November 1964 where he stayed in this city hosted by a colonel in the Turkish Military Intelligence named Ali Cetiner in his own residence. In October 1965, almost After eleven months, , he was go to move to Najaf, Iraq, where he stayed until 1978, when he was encouraged to leave by then-Vice President Saddam Hussein. By this time discontent with the Shah was becoming intense and Khomeini went to Neauphle-le-Château, suburb of Paris, France.