Khomeini served as Supreme Leader of Iran from 1979 to his death on 3 June 1989. An event with long-term impact was the Iran hostage crisis. Following the admission of the former Shah of Iran into the US for cancer treatment, on 4 November 1979, Iranian students seized US embassy personnel, labeling the embassy a "den of spies." 52 hostages were held for 444 days until January 1981.