The Balkan League, of which Greece was a member, declared war on the Ottoman Empire in October 1912. Two months later, the Ottoman fleet attacked the Greek navy, in an attempt to disrupt the naval blockade surrounding the Dardanelles. The Ottoman fleet, which included "Turgut Reis", "Barbaros Hayreddin", two outdated ironclad battleships, nine destroyers and six torpedo boats, sortied from the Dardanelles at 9:30. The smaller ships remained at the mouth of the straits while the battleships sailed north, remaining near to the coast. The Greek flotilla, which included the armored cruiser "Georgios Averof" and "Hydra" and her sisters, had been sailing from the island of Imbros to the patrol line outside the straits. When the Ottomans were sighted, the Greeks altered course to the northeast, in order to block the advance of their opponents. In the ensuing Naval Battle of Elli, the Ottoman ships opened fire first, at 9:50, from a range of about 15,000 yards; the Greeks returned fire ten minutes later, by which time the range had decreased significantly to 8,500 yards. At 10:04, the Ottoman ships completed a 16-point turn, which reversed their course, and steamed for the safety of the straits in a disorganized withdrawal. Within an hour, the routed Ottoman ships had withdrawn into the Dardanelles.