What did you learn about the background to the Iranian hostage crisis?

The Iranian hostage crisis was an international incident that started on November 4, 1979. Iranian students occupied the United States Embassy in the capital city of Tehran. Iranian people disagreed with the authorization of US President Jimmy Carter of allowing the deposed Shah to enter the United States for medical reasons. That was the excuse, but what happened was that Iranian youth-led by Ayatollah Khomeini- wanted to protest for the US interference in the national issues in Iran. The hostages were freed on January 21, 1981.