On November 4, 1979, several hundred students gathered outside the United States Embassy in Tehran intent on occupying the premises and seizing its staff as hostages. Nine months earlier, in one of the final events cementing what would become known as the Islamic Revolution, Ayatollah Ruhollah Khomeini had returned to Iran from exile following the departure of US-supported monarch Shah Mohammad Reza Pahlavi. Shortly after Khomeini’s arrival, in February of that year, the US embassy had been stormed and occupied for the first time, a short-lived but foretelling episode of popular Iranian anger toward the United States. The background to the hostage crisis went back to the first interventions staged by the US in Iran decades before the Islamic Revolution. In 1953, the United States responded to then-Iranian prime minister Mohammed Mosaddegh’s nationalization of the Anglo-Iranian Oil Company by supporting and staging a coup d'état aimed at installing a more friendly leader,Shah Mohammad Reza.RELATED:Rick Perry: I would back Israel strike on Iran nukes siteObama: Keep an 'unprecedented pressure' on IranWhen the Shah was overthrown 26 years later in the revolution of 1979, his subsequent entry to the United States for medical treatment deeply angered Iranians. A group of students loyal to the newly-installed ruling regime of the Ayatollahs decided to show their objections to US policy toward Iran and to dramatically present their demands. Inspired by the previous embassyinvasion, the students, members of the Muslim Student Followers of the Imam's Line, began planning to occupy the US Embassy, take its diplomats and staff hostage and make their demands from inside the gates of the diplomatic mission.Early in the morning of November 4, several hundred students arrived at the embassy’s gates and broke through, seizing all inside. Embassy staff and diplomats who were not in the embassy that day were rounded up and held with those caught earlier in the diplomatic mission. Six Americans, however, managed to escape capture and sought refuge in the Canadian Embassy in Tehran. The six were issued Canadian passports by a special decision of the parliament in Ottowa and were flown out of the country two months later. An additional 13 hostages also made it out of Iran after being released at an early stage in the crisis.The remaining 53 hostages, save one who was later released on medical grounds, were not as lucky. For 444 days, the hostages were held in Tehran while demands were made of the United States and negotiations held for their release. Among the demands made by the Iranian regime were the extradition of the Shah, the release of Iranian assets frozen in the United States, an apology for previous US interventions in Iran and a promise to not impose any additional sanctions onpost-revolutionary Iran.Through Algerian mediators, then-US president Jimmy Carter’s administration held negotiations with the Iranians throughout the crisis, but each time it seemed that an agreement was near, the Iranians backed out and scuttled the deal.Taking into consideration the lack of progress in negotiations and determined to release the hostages, Carter ordered the US military to carry out a rescue mission. In April of 1980, four months after the initial invasion of the embassy, Operation Eagle Claw was launched. Due to technical failures and a complicating sand storm, however, the mission failed with the loss ofseveral helicopters and the death of eight US military personnel.An ambitious second rescue attempt using C-130 Hercules transport planes modified with jet boosters in order to be able to land and take off inside a soccer stadium was also planned. However due to failures in the the aircraft modifications and an eventual breakthrough in negotiations, it was never carried out.Negotiations through the Algerian mediator began to bear fruit in late 1980. By that time, the Shah, who had remained in the United States since late 1979, had died of cancer, making moot one of the key Iranian demands that he be extradited. In the final deal, agreements to pay reciprocal claims were made and the US pledged not to interfere in Iranian affairs in the future.In what was likely an attempt to embarrass Carter, the hostages were released on January 20, 1981, the day the US president left office, putting their release on the watch of US president Ronald Reagan.The consequences of the Iranian Hostage Crisis have not subsided over the years. The episode and its aftermath led to a regime of sanctions leveled against the Islamic Republic that has continued growing to this day. The United States has never returned diplomats to Tehran and conducts all of its diplomatic business through the Swiss Embassy.Perhaps more consequentially, the memory of the crisis continues to influence the distrustful and hostile attitudes the two countries have of each other, a sentiment that has played no small part in the nuclear standoff Iran and the United States are engaged in today.