Who married Maria Gonzaga, Duchess of Montferrat?

Maria Gonzaga or Maria of Mantua (29 July 1609 – 14 August 1660) was a reigning duchess of Montferrat from 1612 until 1660, and regent in Mantua during the minority of her son from 1637 until 1647.

Charles II Gonzaga (22 October 1609 – 30 August 1631) was the son of Charles I, Duke of Mantua, and Catherine de Lorraine-Guise (also known as Catherine de Mayenne). He was the Duke of Nevers and Rethel, together with his father.

In 1621, he succeeded his uncle Henri de Lorraine-Guise as Duke of Mayenne. In 1627 he married his cousin Maria Gonzaga, Marquise of Montferrat and heiress to the Duchy of Mantua. However, Cesare II Gonzaga, Duke of Guastalla and Emperor Ferdinand II rejected her claim to Mantua, leading to the War of Mantuan Succession (1628–1631).

Charles was never Duke of Mantua since he died at Cavriana six years before his father. When the latter died in 1637, Charles's eight-year-old son, Charles II, became Duke of Mantua, his widow Maria acting as regent. His daughter Eleonora became Holy Roman Empress.