Gonzaga was born in Mantua, the son of Marquess Federico I Gonzaga. He had a career as a condottiero acting as Venice's commander from 1489 to 1498. He was the commander-in-chief of the army of the Italian league in the battle of Fornovo, although under the tutorage of his more experienced uncle Ridolfo Gonzaga: although inconclusive, the battle had at least the effect of pushing Charles VIII of France's army back to the Alps.He was described as "short, pop-eyed, snub-nosed and exceptionally brave, and was regarded as the finest knight in Italy"