By the mid-1970s the Shah reigned amidst widespread discontent caused by the continuing repressiveness of his regime, socioeconomic changes that benefited some classes at the expense of others, and the increasing gap between the ruling elite and the disaffected populace. Islamic leaders, particularly the exiled cleric Ayatollah Khomeini, were able to focus this discontent with a populist ideology tied to Islamic principles and calls for the overthrow of the shah. The Shah’s government collapsed following widespread uprisings in 1978 -1979 and consequently an Islamic Republic succeeded his regime.