A French court has found a Corsican shepherd guilty of killing the top French official on the island in 1998.
Colonna had been on the run for five years after the killing
The court in Paris sentenced Yvan Colonna to life in jail for gunning down the governor of the Mediterranean island, Claude Erignac.
Colonna, 47, had denied playing any part in the killing - the most serious political murder in France in decades.
Corsica has been the scene of a campaign of generally low-level separatist violence for three decades.
Mr Erignac was shot three times in the back of the head as he walked to a concert hall in Corsica's capital, Ajaccio, in February 1998. The killing happened in front of the prefect's wife.
Colonna has always denied pulling the trigger, but prosecutors successfully argued during the trial that there was enough circumstantial evidence.
A lawyer for Colonna said he would appeal against the verdict, the AFP news agency reported.
Colonna, portrayed by the separatists as a kind of Robin Hood figure, had been hiding for five years on Corsica, enjoying protection under the local code of omerta (silence).
He was finally captured in a shepherd's hut in Porto-Pollo in 2003.