On Feb 11, 1979, Iran’s army declared its neutrality, paving the way for the collapse of the Shah Mohammad Reza Pahlavi, the United States’ closest ally in the Middle East.

State TV showed large crowds defying frigid weather and carrying Iranian flags while chanting “Death to Israel, Death to America,” trademark chants of the revolution which ousted the United States’ most important ally in the Middle East.

One banner read: “Much to the dismay of America, the revolution has reached its 40th year.”