Temporary head of the US-appointed Iraqi Governing Council, Salim was accused by the Iraqi resistance of collaborating with the occupation authorities.
An author and journalist, he was the head of the Shia Daawa Party in Basra and the editor of several newspapers and magazines.
He was also an opponent of Saddam Hussein for many years and his party once mounted a high-profile attack to assassinate the former Iraqi leader.
But Salim's transition from Iraqi dissident to alleged "American puppet" earned him still more enemies and made him an even bigger target.
Izz al-Din Salim was born in the southern Iraqi city of Basra in 1943.
At least eight people died in the
bombing that killed Salim
At an early age he began studying politics and religion and at 18 won acclaim for his first book.
However, due to his opposition to the ruling Baath Party Salim was forced to leave Iraq in his early 20s.
He subsequently worked as a teacher in Kuwait and then went to Iran to build a career as a journalist. During his career he wrote more than 40 books on political science and religion.
Salim broke away from the main branch of the Daawa Party (Iraq's oldest Shia Muslim organisation) in the early 80s to form his own faction of the party in Basra.
Throughout the 80s, the Daawa Party mounted a campaign against Saddam Hussein and was blamed by Iraqi leaders for provoking the Iraqi attack on Iran in 1980.
During that conflict, most Daawa members either joined Iranian military units or refrained from political activity altogether.
But in July 1982, Daawa members staged a major assassination attempt on Saddam Hussein, bombed the Ministry of Planning in August 1982, and attacked Saddam's motorcade in April 1987.
Salim (R) was the president of the
rotating Iraqi Governing Council
Following these attacks, the group was harshly suppressed and eventually split into several factions. Salim claimed to have survived numerous assassination attempts from Saddam's followers.
Shortly after the US-led invasion of Iraq in 2003, he was appointed a member of the Iraqi Governing Council - one of two Daawa members on the body.
However, when he took his post Salim was one of the lesser known members of the council and was unknown in many parts of Iraq.
He instead drew most of his support from his hometown of Basra.
Nevertheless, as the current incumbent of the rotating council presidency, Salim will be considered a significant scalp in the struggle to undermine the foreign occupation.