The city of Asti, on which Galeazzo had also had designs, was to count as part of Maria's dowry, and Montferrat would be allowed to retain control of it.
[2][3] He succeeded as a child of around 12, and ruled originally under the co-regency of his uncle Otto, Duke of Brunswick-Grubenhagen, and Amadeus VI of Savoy.
His father's will had stipulated that he should remain under his uncle's tutelage until the age of 25; however Otto left for Naples in 1376 to marry Queen Joan I.
Secondotto thus decided to marry Violante (2 August 1377), the daughter of Galeazzo II Visconti, and widow of Lionel of Antwerp, 1st Duke of Clarence, and affirm an alliance with that family against the House of Savoy, Piedmont and Achaea.
He died at Langhirano in the vicinity of Parma in obscure circumstances: he may simply have been the loser in a brawl (he was famously ill-tempered and violent), or he may have been assassinated by an agent of the Visconti.