She was born and died in
Casale, and was the eldest child of
William IX, Marquess of Montferrat, and
Anna d'Alençon. In 1517, when Maria was 8, her mother betrothed her to
Federico II Gonzaga, son of
Isabella d'Este, who later became
Marquis and
Duke of
Mantua. The marriage contract was annulled, however, after Federico accused Maria of attempting to poison his mistress
Isabella Boschetti, wife of the Count of
Calvisano. ==Ancestry==