The event, known as 15 Khordad Uprising in the Iranian calendar, marks the 1963 demonstrations in Iran against the arrest of the later founder of the Islamic Republic Imam Khomeini after a speech in which he attacked the country’s Western-backed Shah and Israel.
On June 5 and 6 of 1963, angry protesters were confronted by tanks and paratroopers in the Iranian cities of Qom, Tehran, Shiraz, Mashhad and Varamin in a crackdown in which about 15,000 people were killed.
The uprising opened a new chapter in a grassroots resistance against the regime of of the former Shah, Mohammad Reza Pahlavi, who faced a legitimacy crisis after a CIA-engineered coup in 1953.
After 15 Khordad Uprising, however, the regime stepped up its heavy-handed crackdown, going on a spree of arrest, jailing and execution of the clergy and dissidents, which fueled further unrest.
Throughout those years, Imam Khomeini was sent to exile in Iraq, Turkey and France for 14 years, before returning to Iran which culminated in the victory of the Islamic Revolution in February 1979.