In a career that spanned over 65 years, Pannella was one of the first European federalists who fought for the creation of the European Union.
He was also at the forefront of many revolutionary changes in Italy, including the divorce referendum in 1974 and the legalization of abortion in 1978.
A staunch defender of civil rights, he also fought on behalf of Eastern Europeans, leading to his arrest in 1968 in Sofia for distributing leaflets against the Communist regime.
Over the years, he carried out several hunger strikes to get his civil rights message across, including one against the death penalty in 2007, a protest which was prompted by the hanging of Saddam Hussein. His most recent hunger strike in 2014 – in protest against conditions in Italian prisons – led to him needing surgery.
Pannella, who was born in the Abruzzo town of Teramo in 1930, began his political career aged 20, becoming a national representative at university level for the Italian Liberal Party.
Marco Pannella during the divorce campaign in 1974. Photo: Wikicommons
He founded the Radical Party, a bastion of Italian liberalism, in 1955. Led by Pannella and Emma Bonino, Italy's former foreign minister, the party was reincarnated as the Italian Radicals in 2001.
On top of all of that he was one of the first promoters of the Green party movements across Europe and was elected to the European Parliament in 1979, serving until 2009.
He a took a hardline approach against Tony Blair, the former British prime minister, during John Chilcot's Iraq inquiry in 2010, saying: “Tony Blair must be asked the right questions at the Iraq inquiry. Mine would be this: why did he boycott the possibility of sending Saddam Hussein into exile, as several Arab countries were trying to request through a resolution to be adopted at the Arab League summit in Sharm el-Sheikh on March 1st 2003?”
He argued that the exile would have avoided any military action.
Aside from the politics, Pannella worked as a journalist in Paris for Il Giorno newpaper in the early 1960s.
He never married and had no children, but had been in a decades-long relationship Mirella Paracchini. In an interview in 2010 he said the relationship between them was “open” and also admitted to being bisexual.
Pannella died on Thursday after being hospitalized in Rome. He had reportedly been battling lung and liver cancer.
Prime Minister Matteo Renzi paid tribute on Twitter, saying Pannella was an “extraordinary protagonist of life” and not just of Italian politics, “one might say he was transnational”.