In the meantime, the Turks had suffered a grave defeat by the Austrians in the Battle of Petrovaradin on 5 August 1716. Venetian naval efforts in the Aegean Sea and the Dardanelles in 1717 and 1718, however, met with little success. With the Treaty of Passarowitz (21 July 1718), Austria made large territorial gains, but Venice lost the Morea, for which its small gains in Albania and Dalmatia were little compensation. This was the last war with the Ottoman Empire. By the year 1792, the once-great Venetian merchant fleet had declined to a mere 309 merchantmen.