The term Islamic republic has been used in different ways. Some Muslim religious leaders have used it as the name for a form of Islamic theocratic government enforcing sharia, or laws compatible with sharia. The term has also been used for a sovereign state taking a compromise position between a purely Islamic caliphate and a secular, nationalist republic.
The term is currently used in the official title of three states – the Islamic Republics of Pakistan, Mauritania, and Iran. Pakistan first adopted the title under the constitution of 1956. Mauritania adopted it on 28 November 1958. Iran adopted it after the 1979 Iranian Revolution that overthrew the Pahlavi dynasty. Despite having similar names, the countries differ greatly in their governments and laws.