Duchy of Montferrat in the context of "Montferrat"

The War of the Mantuan Succession, 1628 to 1631, was caused by the death in December 1627 of Vincenzo II, last male heir from the House of Gonzaga, long-time rulers of Mantua and Montferrat. Their strategic importance led to a proxy war between the French-backed Duke of Nevers, and the Duke of Guastalla, supported by Spain. It is considered a related conflict of the 1618 to 1648 Thirty Years' War.

Fighting centred on the French-held fortress of Casale Monferrato, which the Spanish besieged twice. French intervention on behalf of Nevers in April 1629 led Emperor Ferdinand II to support Spain by transferring troops from Northern Germany. They captured Mantua in July 1630, but failed to take Casale. Ferdinand withdrew his troops in response to Swedish intervention in the Thirty Years' War, and both sides agreed a truce in October 1630.

The marquises and dukes of Montferrat were the rulers of a territory in Piedmont south of the Po and east of Turin. The March of Montferrat was created by Berengar II of Italy in 950 during a redistribution of power in the northwest of his kingdom. It was originally named after and held by the Aleramici. In 1574, Montferrat was raised to a duchy by Emperor Maximilian II (see Duchy of Montferrat).