The greatest Turkish effort was directed against Sebenico, in today's Croatia, which was besieged in August–September 1647. The siege failed, and in the succeeding year the Venetians recovered several fortresses inland, such as Clissa. In Crete, however, the situation was more serious. Throughout all the war the Venetian strategy was to blockade the Dardanelles in order to surprise the Turkish fleet on its way to supply the troops on Crete. There were some signal successes, including two victories in the Dardanelles in 1655 and 1656, but they failed to alter the strategic situation. The next year there was a three-day-long sea-battle (17–19 July 1657), in which the captain Lazzaro Mocenigo was killed by a falling mast, and turning into a crushing defeat. With the end of the war between France and Spain in 1659, Venice received more aid from the Christian states than the small contingents which she had received in the first years. In 1666 an expedition to retake Khania failed, and in 1669 another attempt to lift the siege of Candia with joint action on land with the French contingent and by sea under Mocenigo also turned out to be a failure. The French returned home, and only 3,600 fit men were left in the fortress of Candia. Captain Francesco Morosini negotiated its surrender on 6 September 1669. The island of Crete was ceded, except for some small Venetian bases, while Venice retained the islands of Tinos and Cerigo, and its conquests in Dalmatia.