Grand Ayatollah Hussein-Ali Montazeri (Persian: حسینعلی منتظری [hosei̯næˈliː-e montæzeˈɾiː] ; 24 September 1922 – 19 December 2009) was an Iranian Shia Islamic theologian, Islamic democracy advocate, writer and human rights activist. He was one of the leaders of the Iranian Revolution and one of the highest-ranking authorities in Shīʿite Islam. He was once the designated successor to the revolution's Supreme Leader, Ayatollah Khomeini, but they had a falling-out in 1989 over government policies that Montazeri claimed infringed on people's freedom and denied them their rights, especially after the 1988 mass execution of political prisoners. Montazeri spent his later years in Qom and remained politically influential in Iran, but was placed in house arrest in 1997 for questioning "the unacco