The Relief of Genoa took place between 28 March 1625 and 24 April 1625, during the Thirty Years' War. It was a major naval expedition launched by Spain against the French-occupied Republic of Genoa, of which the capital Genoa was being besieged by a joint Franco-Savoyard army composed of 30,000 men and 3,000 cavalry. I have been careful until now to avoid anything that could provoke an open war between the two crowns; [but] if the king of Spain takes up arms against me, I will be the last to lay them down. — Louis XIII to Francesco Barberini, early 1635