[1] The direct cause of the conflict was the death of duke Francesco IV Gonzaga of Montferrat and Mantua on 22 December 1612 without male heirs.

The treaty stipulated that when the male descendants of the marquis of Montferrat went extinct, those of Yolande (and thus the House of Savoy) would succeed in the marquisate, to provide the daughters with money.

That year, the Peace of Asti was drawn up, determining that Savoy should relinquish its claims on Montferrat, but the treaty was never signed and the war continued.

Eventually, Savoy and Spain finally signed the Peace of Asti in 1617, which confirmed Ferdinando as the legitimate heir of Francesco.

Despite marrying, following the resignation of Ferdinando and the expulsion of Vincenzo from the Sacred College of Cardinals (for violating the celibacy), neither produced any legitimate children.