They were formidable from the territories and castles which they possessed, and by their alliance and friendship with Charles, King of Naples.

The power of the Colonna family became offensive to Boniface, who, besides, hated the two Cardinals for having opposed the renunciation of Celestine V., which Boniface had fraudulently obtained.
Boniface procured a crusade against them.

They were beaten, expelled from their castles, and almost exterminated; they implored peace, but in vain; they were driven from Rome, and obliged to seek refuge, some in Sicily and others in France.

During the time of their exile, Boniface proclaimed it a capital crime to give shelter to any of them.
The Colonnas finally returned to their dignities and property, and afterwards made successful war against the house of their rivals, the Orsini.
John Colonna, the Cardinal, brother of the Bishop of Lombes, and son of old Stefano, was one of the very ablest men at the papal court.

He insisted on our poet taking up his abode in his own palace at Avignon.
"What good fortune was this for me!" says Petrarch.