He co-ruled in Milan with his nephew Azzone Visconti and his brother Giovanni, until Azzones's death in 1339. He also took part in the victorious battle of Parabiago against his other nephew, Lodrisio, who had set a mercenary army to capture Milan.
He married three times: to Violante of Saluzzo, daughter of Thomas I of Saluzzo, then to Caterina Spinola, daughter of Obizzo Spinola, and, in 1349, to Isabella Fieschi, niece of Pope Adrian V, who gave him his sole legitimate son, Luchino Novello. He was a capable military commander and lord, but was also famous for his cruel behaviour. In January 1349 he discovered Isabella's unfaithful behaviour, and announced for her a terrible punishment. A few days later he was found poisoned, the people soon nicknaming his wife Isabella del veleno ("Isabella of poison").
He was succeeded by his nephews Bernabò, Galeazzo and Matteo II, whom he had exiled from Milan in 1346. The infidelities of Isabella were used by him and his relatives to oust Luchino Novello from the heritage.