After the Iranian Revolution of 1979 and referendum to create the Islamic Republic on March 29 and 30, the new government needed to craft a new constitution. Ayatollah Ruhollah Khomeini, ordered an election for the Assembly of Experts, the body tasked with writing the constitution.[1] The assembly presented the constitution on October 24, 1979, and Supreme Leader Ruhollah Khomeini and Prime Minister Mehdi Bazargan approved it. This was also approved in December 1979 constitutional referendum.
The 1979 Constitution designated the Supreme Leader as the head of state and the President and Prime Minister as the heads of government. The post of Prime Minister was abolished in 1989.