"The form of government of Iran is that of an Islamic Republic, endorsed by the people of Iran on the basis of their long-standing belief in the sovereignty of truth and Qur'anic justice, in the referendum of...(March 29 and 30, 1979], through the affirmative vote of a majority of 98.2% of eligible voters, held after the victorious Islamic Revolution led by the eminent marji' al-taqlid, Ayatullah al-Uzma Imam Khomeyni."
January 1, 1970
https://en.wikiquote.org/wiki/Constitution_of_the_Islamic_Republic_of_Iran