The shah saw himself foremost as a Persian king and in 1971 held an extravagant celebration of the 2,500th anniversary of the pre-Islamic Persian monarchy. In 1976, he formally replaced the Islamic calendar with a Persian calendar. Religious discontent grew, and the shah became more repressive, using his brutal secret police force to suppress opposition. This alienated students and intellectuals in Iran, and support for Khomeini grew. Discontent was also rampant in the poor and middle classes, who felt that the economic developments of the White Revolution had only benefited the ruling elite. In 1978, anti-shah demonstrations broke out in Iran’s major cities.
On September 8, 1978, the shah’s security force fired on a large group of demonstrators, killing hundreds and wounding thousands. Two months later, thousands took to the streets of Tehran, rioting and destroying symbols of westernization, such as banks and liquor stores. Khomeini called for the shah’s immediate overthrow, and on December 11 a group of soldiers mutinied and attacked the shah’s security officers. With that, his regime collapsed and the shah fled.