Ayatollah Ali Khamenei is the highest authority in Iran. As Supreme Leader he has the final say on all matters political, far beyond the powers of the president.Positioned at the top of Iran’s power structure, he appoints both directly and indirectly the members of the influential Guardian Council, which monitors the constitution. The body can also bar candidates standing in elections and Khamenei’s twenty years in power have seen a string of conservative appointments at the expense of reformers. Before coming to power, Khamenei was also able to cement his position as Supreme leader through the contacts he made while he was president under Ayatollah Khomeini. On the first of February 1979, Khomeini arrived in Teheran after almost 15 years in exile, fronting the Islamic Revolution which would end the reign of the Shah, Mohamed Reza Pahlavi. His ‘White Revolution’ — a programme aimed at modernising and westernising Iran — would alienate the Mullars and bring about large-scale social unrest. Two months later Iran saw the establishment of a theocracy giving ultimate power to the clergy. Khomeini proclaimed the Islamic Republic following a referendum. Between 1981 and 1989, during Iran’s war against Iraq, Khamenei as president found himself at odds with his prime minister Mir Hossein Mousavi on a range of social, economic and religious matters. The rift was swept under the carpet because Khomeini gave Moussavi his full support. On Khomeini’s death, however, Ayatollah Khamenei revised the constitution, abolishing the post of prime minister. Friction between conservatives and reformers has surfaced several times and Khamenei has nearly always ruled in favour of the hardliners. The only exception came in 2002 when he commuted the sentence of pro-reform academic Hashem Aghajari, from death to prison. Aghajari had said Muslims should re-interpret Islam rather than blindly follow leaders.