Stefano was probably born at the end of the fifteenth century, of the Palestrina branch of the Colonna family and of Orsina Orsini. As a mercenary, in the early 1520s, he served in the Imperial (1522-1524), Papal (1524-1528) and French army (1528-1529). Enlisted by the Florentine Republic in 1529, Stefano Colonna was put in charge of the city with his men. On 20 June 1530, Stefano tried to break the blockade around Florence by attacking the German camp near San Donato in Polverosa, but he failed. After the war of Florence, Stefano went to fight for the King of France in Lombardy (1536-1538). In 1538, he was recruited by Pope Paul III Farnese as captain general of the infantry forces, remaining in his service until 1541, when he went to serve Cosimo I de’ Medici. He died in Pisa on 8 March 1548.
Bibliography and sources:
Franca Petrucci, Stefano Colonna, in Dizionario Biografico degli Italiani, 27, 1982, s.v. Alessandro Serio, Una gloriosa sconfitta. I Colonna tra papato e impero nella prima Età moderna, Roma, Viella, 2008