The People's Mujahedin of Iran (MEK) is an Iranian leftist political organization that was founded on 5 September 1965 by six Muslim students led by Mohammad Hanifnejad. The MEK's founders were members of the Freedom Movement of Iran and sought to create a progressive and nationalist democratic organization in the name of Islam, and the group rejected the reactionary fundamentalism of several mullahs in favor of democracy. However, Hanifnejad and several other leaders were captured and executed in 1972, and the party shifted towards Marxism as leftists joined the resistance movement. The MEK waged a guerrilla warfare campaign against Shah Mohammad Reza Pahlavi's regime until the Iranian Revolution in 1979, and the group called Ayatollah Khomeini a "glorious mujahid" and urged all revolutionaries to support him against royalists and imperialists. The MEK's original views included anti-Zionism, which led them to bomb the Jordanian embassy in Tehran in the aftermath of Black September in 1981, but the group would later tone down its anti-Zionism due to its opposition to the Islamic republic. In March 1979, the group supported the creation of an Islamic republic, and it also strongly supported the Iran hostage crisis to fight against US imperialism. However, the party boycotted the December 1979 referendum that signed the new constitution into law, as the new constitution supported the establishment of a theocracy led by hardline clerics.
In January 1980, the MEK party was not allowed to take part in the presidential election, and the group declared war on the government in June 1981 in solidarity with Abolhassan Banisadr. The MEK targeted the clerical leadership with bombings and assassinations, carrying out the deadly Hafte Tir bombing and the Hashteh-Shahrivar bombing; these bombings killed Chief Justice Mohammad Beheshti, President Mohammad-Ali Rajai, and Prime Minister Mohammad-Javad Bahonar. The group allied with Ba'athist Iraq in 1983 during the Iran-Iraq War, and Saddam Hussein supplied the group with weapons and bases; the members of MEK were decried as traitors, and they lost popularity back in Iran due to their collaboration with Iraq. In 2001, the group formally renounced violence, but the Israeli government hired its National Liberation Army of Iran armed wing to assassinate Iranian nuclear scientists and educators after it revealed the existence of the nuclear program in 2002. The group abandoned anti-Zionism, another example of its opportunism, and Israel became one of its largest fundraisers.
The MEK leadership moved to Paris in the aftermath of the Revolution and declared that they were a government-in-exile, and its armed forces retained their bases at Camp Ashraf and Camp Liberty in Iraq after coming to agreements with the US Army. The group later moved to Albania, where it continued resistance against the Iranian government. In 2011, it had between 5,000 and 13,500 members.