The Iran Hostage Crisis began on November 4, 1979, when a group of Iranian students stormed the U.S. Embassy in Tehran, taking 52 American diplomats and citizens hostage. This event was a response to the U.S. allowing the exiled Iranian leader, Shah Mohammad Reza Pahlavi, to enter the United States for medical treatment. The crisis lasted 444 days, creating significant tension between the two countries. During the hostage situation, the U.S. government attempted various diplomatic and military solutions, but none were successful. The hostages were finally released on January 20, 1981, coinciding with the inauguration of President Ronald Reagan. The crisis had lasting effects on U.S.-Iran relations and American foreign policy.