The operations of the Knights in the seventeenth century were mainly carried out in alliance with the Venetians, who were the one Power who continued to resist the Turk at sea. They were still lords of the great island of Crete, which lay athwart the trade routes of the Levant, and only by its conquest would the Ottoman control of the Eastern Mediterranean be complete. In 1645 Ibrahim I. declared war on Venice and besieged Candia; but the attack was so remiss that success seemed impossible. The Knights of Malta threw themselves into the struggle on the side of the Venetians, feeling bound in honour to do so, as the refuge of Maltese galleys in Venetian harbours was the Turkish pretext for war. In 1656 Mocenigo, the Venetian Admiral, with the aid of the Knights, won a brilliant victory off the Dardanelles, capturing Lemnos and Tenedos. This imminent peril brought Mohammed Kiuprili to power as Grand Vizier, and the war was thenceforward conducted with great energy by the Turks. Year after year volunteers flocked to Candia to save the last Christian outpost in the Levant, but it was all fruitless, and in 1669 the island, with the exception of three ports, was surrendered to the Turks—their last important conquest in Europe, and the final term of their advance.
The seventeenth century saw the gradual displacement of galleys in favour of sailing ships. The long voyages across the Atlantic and to the East had given great impetus to the development of the sailing vessel; its increasing use, and the entrance of England and Holland into the Mediterranean, had shown the Powers of that sea its superiority over the galley; finally, slaves were becoming more difficult to obtain in sufficient quantities, while criminals had never been a satisfactory source of supply. The Knights were slow in changing the oar for the sail, and to the end kept a small squadron of galleys as well as men-of-war. When Napoleon captured the island, in 1798, he found there two men-of-war, one frigate, and four galleys.
The pride and the renown of the Order had always demanded a salute from the warships of other nations, and even the mighty Louis XIV. yielded this privilege to the little squadron. There is extant an interesting correspondence between Charles ii. and the Grand Master, Nicholas Cottoner, on the subject of salutes. A squadron of the British Fleet, under Admiral Sir John Narborough, had refused to salute Valetta unless assured of a response from the guns of the fortress—a mark of respect that the Order was unwilling to pay to the British flag. The Grand Master had also ventured to doubt Narborough’s rank as Admiral, but the affair was amicably settled to the satisfaction of all.