Why did iranian students occupy the us embassy in Tehran?

Question

in the year 1979

* short and clear answer please

Answer 1

They wanted President Carter to send the Shah of Iran, Mohammad Reza Pahlavi, back to face trial and execution.

The occupation and looting of the embassy, the taking of diplomats hostage, was an act of war.  When the history of the "war on terrorism" is written a 100 years from now November 4, 1979 will be recognized as the date World War III started.

Answer 2

AS I recall, they had always been upset with the USA for supporting Shah of Iran and the USA agreed to allow the Shah to enter the USA to go to a hospital.