The Islamic Revolution in Iran reached its climax on 11 February 1979, when the Pahlavi monarchy effectively collapsed and revolutionary forces took control of the state.

Key dates in brief

  • Main revolutionary period: 1978–1979, often simply called the “1979 Iranian Revolution.”
  • Fall of the monarchy / “victory of the revolution”: 11 February 1979 (22 Bahman in the Iranian calendar), now marked annually as the official anniversary.
  • Formal establishment of the Islamic Republic: national referendum on 30–31 March 1979, with the Islamic Republic proclaimed on 1 April 1979.

So, if you’re answering “when was the Islamic Revolution in Iran,” the historically accepted short answer is: in 1979, with the decisive victory on 11 February 1979.