Massoud Rajavi became the leader of the People's Mujahedin of Iran (MEK) in 1979. In 1985, he married Maryam Rajavi, who became the co-leader of the MEK. After leaving Iran in 1981, he resided in France and Iraq. He disappeared shortly before the 2003 invasion of Iraq and it is not known whether he is still alive. This has left Maryam Rajavi as the public face of the MEK.

The People's Mojahedin Organization of Iran (PMOI), also known as Mojahedin-e-Khalq (MEK) or Mojahedin-e-Khalq Organization (MKO), is an Iranian dissident organization that was previously armed but has now transitioned primarily into a political advocacy group. Its headquarters are currently in Albania. The group's ideology is rooted in "Islam with revolutionary Marxism," but after the Iranian Revolution became about overthrowing the Government of the Islamic Republic of Iran and installing its own government. At one point the MEK was Iran's "largest and most active armed dissident group," and it is still sometimes presented by Western political backers as a major Iranian opposition group, but it is also deeply unpopular today within Iran, largely due to its siding with Iraq in the Iran–Iraq War.