In 1628 Venice was involved in Italian politics for the first time in more than a century. On the death of Ferdinando I Gonzaga, duke of Mantua and Montferrat, the succession devolved upon a French prince, Charles of Gonzaga-Nevers. This changed the balance of power in northern Italy, which had until now been controlled by the Spanish through Milan. In the ensuing war, Venice was allied with France against the Habsburgs and Savoy. The Venetian army was defeated in an attempt to come to the aid of Mantua, which was under siege by German troops, and Mantua itself was savagely sacked. The peace which recognized Charles of Gonzaga-Nevers as duke of Mantua and Monferrato was made practically without Venice's participation. War brought plague in 1630. In 16 months 50,000 people died in Venice, one third of the population. The first stone of the church of Santa Maria della Salute in the city was laid as a thanks offering for the end of the plague.