a Marxist sentenced 30 years ago for supporting terrorism in Italy, wrote with Michael Hardt a book, Empire (published by Harvard university Press).

He is the man accused of leading the Italian revolutionary left in the 1970s. The story goes back to 1979 when, as a respected professor at the University of Padua, Negri was arrested and accused of being the secret leader of the Red Brigades, the terrorist group that had kidnapped and assassinated Aldo Moro, the president of the Christian Democratic Party.

The story of his imprisonment is still alive and goes on because in meantime he went out and back to prison since he fled to France in 1983. He was sentenced in his absence, despite Amnesty International's condemnation of "serious legal irregularities" at the trial. Then, in 1997 - after 14 years' exile in Paris - he gave himself up to the Italian authorities and returned to Italy voluntarily in the hope that his action would contribute to the resolution of the problem of the exiles and prisoners who are wanted or convicted for the political activities of the 1970s in Italy, the so-called "years of lead". He was sent to prison but allowed out to his home every day, provided he returned each night. Now he need not go to prison any more: he is now allowed to sleep at home, providing he does not go out from 7pm to 7am.

There is a theory in his book, written with one of his former students, Michael Hardt. Globalization isn't simply the latest phase in the history of imperialism and nation-states, the authors declare. It's something radically new. Where other scholars and the media depict countries vying for control of world markets, Hardt and Negri instead discern a new political system and a new form of power taking root. They call it Empire. They wrote what people have been thinking but not really articulated, Negri said. Globalisation is a new capitalist "empire", uniting all states under a single logic. "Our political task," argues Negri, "is not simply to resist these processes but to redirect and reorganise them towards new ends."