1618 Conspiracy of Don Pedro de Toledo, governor of Milan, the duke of Osuna, and the marquis of Bedmar to destroy Venice. It is betrayed to the Council of Ten and thwarted.
1620 The Catholics in the Grisons revolt against the Protestant government. Philip III sends the governor of Milan to help the Catholics. He occupies the Valtelline.
1624 France, Savoy, and Venice unite against Spain in the war in the Grisons.
1625 The duke of Savoy and a French army make an attempt to capture Genoa. The Germans and Spaniards invade Savoy and the duke is obliged to abandon the siege.
1626 On the death of the last of the Della Rovere family the duchy of Urbino is annexed to the papal states.
1627 On the death of the duke of Mantua, Charles Emmanuel again seizes Montferrat.
1628 France and Venice oppose the duke of Savoy. Spain and Austria assist him. The Spaniards seize Casale. Plot of Vachero and others in Genoa to place the city under the protection of Charles Emmanuel. It is discovered and its leader executed.
1629 Treaty of Susa between France and Savoy. Spain and the emperor refuse to ratify it.
1630 Death of Charles Emmanuel, succeeded by his son Victor Amadeus I. The imperial army seizes Mantua.
1631 The Montferrat question settled by the treaty of Cherasco. Mantua and Montferrat are given to Charles, duke of Nevers. Savoy gets a small portion of Montferrat and Pinerolo is ceded to France.