After his return to Mantua from Rome his prosperity was at its height, until the death of his wife.
At the latters death in 1830 Ferdinand now flew to arms, and the Austrian garrisons, except in the Quadrilateral (Verona, Peschiera, Mantua and Legnano) were expelled.
In the Netherlands by joining hands with the Dutch, and on the Rhine by uniting with the Swedes; but the bad organization of the French armies, the double invasion of the Spaniards as far as Corbie and the imperial forces as far as the gates of Saint-Jean-de-Losne (1636), and the death of his allies, the dukes of Hesse-Cassel, Savoy and Mantua at first frustrated his efforts.
The rest of his life was passed in Verona, Mantua and Rome - chiefly Mantua; Venice and Florence have also been named, but without confirmation.
Commerce is chiefly agricultural and is stimulated by a good position in the railway system, and by a canal which opens a water-way by the Panaro and the Po to the Adriatic. Modena is the point at which the railway to Mantua and Verona diverges from that between Milan and Bologna, and has several steam tramways to neighbouring places.
His attempt to capture Geneva by treachery (1602) failed, and although on the death of Francesco Gonzaga, duke of Mantua and Montferrat, he seized the latter city (1612) he was forced by Spain and her allies to relinquish it.
Milan and Mantua remained in the hands of the Austrians.
At Mantua he designed the church of Sant' Andrea and at Rimini the celebrated church of San Francesco, which is generally esteemed his finest work.
During the War of the Spanish Succession, the French under the duke of Vendome occupied it; and during the siege of Mantua in 1796, the Austrians under Wiirmser were defeated here by the French under Augereau, who was later created by Napoleon duke of Castiglione.
She was the last heiress of the great house of Canossa, whose fiefs stretched from Mantua across Lombardy, passed the Apennines, included the Tuscan plains, and embraced a portion of the duchy of Spoleto.