The son of Tommasino Fregoso and Caterina Malaspina, he first trained in Corsica, then moved to Rome where he received a cavalry command by Pope Julius II.

In 1506, together with his kinsman Ottaviano di Campofregoso, he led an army against Genoa but halted his march after he was reconciled with the nobles who had allied with France.

In 1512 he led another military expedition against Genoa, which he freed from the last French garrisons.

His rule lasted for a year, after plots of the Fieschi and Adorno families led again the Republic towards the French King Louis XII.

Giano left the city on a ship on 25 May 1513, serving the rival Republic of Venice as a land commander in the Wars in Lombardy.