The basis of their agreement was laid in the Treaty of Barcelona in 1529.

It was ratified and secured by the Treaty of Cambray in the same year.

By the former of these compacts Charles and Clement swore friendship.

Clement promised the Imperial crown and the investiture of Naples to the King of Spain.

Charles agreed to reinstate the Pope in Emilia, which had been seized from Ferrara by Julius II.; to procure the restoration of Ravenna and Cervia by the Venetians; to subdue Florence to the House of Medici; and to bestow the hand of his natural daughter Margaret of Austria on Clement's bastard nephew Alessandro, who was already designated ruler of the city.