After landing in the Greek province of Mo-reia, the Russians surrounded the Tur-kish fortress of Koron, and on 10 April 1770 took Navarino, capturing 45 guns. In May, Elfinston, with three ships of the line and two frigates, twice attacked the Turkish fleet of Kapudan-Pasha Hassan-bey. The Turkish forces were three times superior in number, but the constant assaults of the Russians forced them to retreat to the Aegean Sea. Count Alexey Orlov, who was at that time General-in-Chief of all the armies, was named by Catherine II Commander-in-Chief of the Fleet. He immediately combined the Spiridov and Elfinston squadrons, and began a search for the enemy. On 23 June 1770 he sighted the Turks lying at anchor in the Chios Strait. The enemy had 73 vessels, among them sixteen ships of the line and six frigates formed in two lines. The Russians could advance only nine ships of the line and three frigates; the Turks boasted twice as many guns. In counsel with his advisors, Count Orlov convened a Council of War. On the afternoon of 24 June the Russian fleet began to fire upon the Turkish centre and vanguard. The Russians were led by Spiridov on the Yevstafy, with Elfinston on the 80-gun Svyatoslav bringing up the rear of the column. Orlov's flag was flying on the 66-gun ship Three Hierarchs in the centre of Commodore Samuel Greig's formation.
The Turks opened fire on the Yevstafy. The Russian ship returned their fire and extensively damaged the 80-gun Real-Mustafa, which was commanded by the Turkish admiral. The Russians boarded the enemy ship, but at that moment the burning mast of the Real-Mustafa fell on the Yevstafy and ignited its powder supply. With a terrific roar both ships exploded and sank. Admiral Spiridov, nonetheless, succeeded in escaping the conflagration, and managed to transfer his flag onto the Tri Svyatitelya [Three Saints]. The rest of the Russian fleet continued the attack. The Turks, now in retreat, cut their anchor cables and hid in the narrow Chesma Bight.
Shortly after the battle the Russians decided to attack the enemy on the night of 26 June. Commodore Greig's unit, consisting of four ships of the line, two frigates, one bombardment ship, Grom and four fire ships, entered the Chesma Bight. At approximately midnight the Europe, commanded by Captain Klokachev, opened fire on the Turks. He was supported by Greig on the Rostislav and by other ships of the line and frigates. Within an hour and a half the water in the bight was illuminated by the light of the first burning Turkish ship. Greig sent out bombardment ships and branders to attack the enemy. One of the branders was commanded by Lieutenant Ilyin, who set fire to his brander and then rammed it into one of the larger Turkish war-ships. The brander was tightly hooked onto the Turkish vessel with grapnels; the enemy ship caught fire and then its powder ignited. It ex-ploded with such force that neighbouring Turkish vessels started to ignite, and soon the en-tire Turkish fleet was aflame. The Russians captured the 60-gun ship Rhodos and five galleys; by 9 a. m. the Turkish fleet had ceased to exist.
The Battle of Chesma was the decisive naval victory over the Ottoman Empire. Not counting the ships themselves, the Turks lost eleven thousand seamen. Russian losses totalled 534 seamen, the majority of whom perished aboard the Yevstafy.
For the victory at Chesma several seamen were awarded the Order of Saint George, created by decree of Catherine II on 26 November 1769: Captains Klokachev and Khmetevsky, Lieutenant-Commander Perepechin (of the Grom) and Lieutenant Ilyin. The Russian fleet now commanded the Aegean Sea, blocking all seaborne supply routes to the capital of the Ottoman Empire and raiding Turkish seaside fortresses. In November of 1771 the landing troops aboard Russian vessels set fire to an admiralty and two enemy ships of the line in Mitilen. In all, twenty ships of the line, based in the port of Aousa on Paros Island, were sent to the Mediterranean.
In July 1773, a detachment under Captain Ivan Kozhukhov, consisting of five frigates and fourteen smaller ships, landed troops at the fortress of Beirut. Russian forces besieged the town for over two months, capturing the fortress, two smaller galleys and 41 cannon and exacting a tribute of thirty thousand piasters. Since Beirut had traditionally helped fund the military efforts of the Turkish Sultan, his situation was now considerably weaker.
The battle for Patras and its capture was one of the most important Russian victories in the Mediterranean. On 28 October 1772, the unit of Captain Mikhail Konyaev, comprising two ships of the line and two frigates, destroyed eight Turkish frigates and eight shebekas defending the fortresses of Patras and Lepanto.
The triumphs of the Russian fleet in the Mediterranean Sea served to exalt Russia's stature among European nations. The growing respect accorded Russia was also a psychological incentive that Russia needed to defeat the indefatigable, and seemingly omnipotent, Turks. The prowess of Russia's ships demonstrated that Catherine the Great's efforts were not in vain and that, by continuing the maritime policies laid down by Peter I, she saw in Russia's maritime potential the glory and majesty of the Russian State.