They were convicted of involvement in a series of bombings five years ago that killed ten people and destroyed a number of historic buildings.

Two of the three bosses, Leoluca Bagarella and Filippo Graviano, both notorious Sicilian Mafia gangsters, are in custody. The third, Bernardo Provenzano, who remains on the run, was sentenced in his absence.

Havoc left by the mafia bombs

They were found guilty of organizing the detonation of a car bomb near the world-famous Uffizi picture gallery in Florence in May 1993.

The bomb killed five people and injured 37 more as well as destroying and damaging important works of art.

Campaign to 'destabilise' government

The Mafia bombing in Florence was followed two months later by two more car bombs in Rome which injured 22 people and caused serious damage to two Rome churches.

The prosecution case was that these were acts of cultural terrorism carried out on the Italian mainland by the Sicilian Mafia with the aim of destabilising the government in Rome and harming Italy's image abroad.

Ten more defendants were given sentences ranging from 12 to 28 years in prison; two defendants were acquitted.

Help of technology

Investigators got on the track of the criminals through a mobile telephone intercept. Over more than a year, more than a million telephone calls were analysed on a database created by a special police department set up to combat Mafia crime.

This patient detective work led to the trial which ended today and which has been going on for the past year-and-a-half.