The Russo-Turkish War of 1768–1774 was a major armed conflict that saw Russian armies victorious against the Ottoman Empire. Russia's victory brought the Yedisan between the rivers Bug and Dnieper, and Crimea into the Russian sphere of influence. Though a series of victories accrued by the Russian Empire led to substantial territorial conquests, including direct conquest over much of the Pontic–Caspian steppe, less Ottoman territory was directly annexed than might otherwise be expected due to a complex struggle within the European diplomatic system to maintain a balance of power that was acceptable to other European states and avoided direct Russian hegemony over Eastern Europe.
Nonetheless, Russia took advantage of the weakened Ottoman Empire, the end of the Seven Years' War, and the withdrawal of France from Polish affairs to assert itself as one of the continent's primary military powers. The war left the Russian Empire in a strengthened position to expand its territory and maintain hegemony over the Polish–Lithuanian Commonwealth, eventually leading to the First Partition of Poland. Turkish losses included diplomatic defeats which led to its decline as a threat to Europe, the loss of its exclusive control over the Orthodox millet, and the beginning of European bickering over the Eastern question that would feature in European diplomacy until the dissolution of the Ottoman Empire in the aftermath of World War I.
The war followed internal tensions within Poland which indirectly challenged the security of the Ottoman Empire and its ally, the Crimean Khanate. The true power behind the Polish throne was the Russian ambassador Nicholas Repnin and the Imperial Russian Army, with King Stanisław August Poniatowski being elected due to his ties as a former favourite of the Empress Catherine II of Russia. Repnin had forcefully imposed the Perpetual Treaty of 1768 between Poland and Russia, which was disadvantageous to Poland geopolitically, challenged the political supremacy of Poland's Catholic faith, prevented reform of the liberum veto, and allowed Warsaw's occupation by Russian troops. Rising unrest led to the massive revolt of the Bar Confederation, which became an alliance of noble, Roman Catholic, and peasant rebels.
In the fortified town of Bar, near the Ottoman border, the Bar Confederation was created on 29 February 1768, led by a Polish nobleman named Casimir Pulaski. While the Russian army heavily outnumbered the confederates and defeated them several times in direct battle in Podolia, Ukraine, bands of rebels waged a low-scale guerrilla war throughout Ukraine and southern Poland. On 20 June 1768, the Russian Army captured the fortress of Bar but when one band of surviving confederates fled to the Turkish border, pursuing troops, including Zaporozhian Cossacks, clashed with janissary garrison troops. Polish revolts continued to trouble Russia throughout the war and make it impossible for Catherine II to keep control of Poland.
In the Ottoman Empire, revolts were widespread. Many noble factions had risen against the power of Sultan Mustafa III and would proceed to break away from the Ottoman Empire. In addition to this decentralization of the empire the Ottomans also faced the revival of a unified Persia, which rose to oppose the Turks in Iraq.
Upon the outbreak of the war, the Ottomans seemed to have the upper hand as Russia was suffering from financial strain as a consequence of its involvement in the Seven Years' War. The Ottoman Navy capitalized on the inferiority of the Imperial Russian Navy, even though Russia employed British officers to address this weakness. The Ottomans dominated the Black Sea, giving it the advantage of shorter supply lines. The Ottomans were also able to levy troops from their vassal state, the Crimean Khanate, to fight the Russians, but their effectiveness was undermined by constant Russian destabilization of the area. In the years preceding the war the Ottoman Empire had enjoyed the longest period of peace with Europe in its history (1739–1768). Nevertheless, the Ottoman Empire faced internal division, rebellion and corruption compounded by the re-emergence of a unified Persian leadership, under Nader Shah. One clear advantage for the Ottomans was its superior numbers as the Ottoman army was three times the size of its Russian counterpart. However, the new Grand Vizier Mehmed Emin Pasha would prove himself to be incompetent militarily. The Russian army massed along the borders with Poland and the Ottoman Empire, which made it difficult for Ottomans troops to make inroads into Russian territory.
Not content to let the Polish enemy flee over the border, Cossacks followed them into the Ottoman Empire. In the summer of 1768, Mustafa III received reports that the town of Balta had been massacred by Russian paid Zaporozhian Cossacks. Russia denied the accusations, but it was reported that the Cossacks "certainly razed Balta and killed whomever they found". With the confederates of Poland and the French embassy pushing the sultan along, with many pro-war advisors, the sultan on October 6 imprisoned Aleksei Mikhailovich Obreskov and the entire Russian embassy's staff, marking the Ottoman's declaration of war on Russia.
After her victories in the war, Catherine II was depicted in portraits dressed in the military uniforms of Great Britain, initially a willing ally because of the trade between the two countries. Great Britain needed bar iron to fuel its nascent Industrial Revolution, as well as other products such as sailcloth, hemp, and timber for the construction and maintenance of its Navy; Russia could provide all these. When the tide of the conflict turned in Russia's favour, Britain limited its support, now seeing Russia as a rising competitor in Far Eastern trade, rather than merely as a counterbalance to the French Navy in the Mediterranean. While Russia remained in a superior position in the Black Sea, the withdrawal of British support left Russia unable to do more than shorten its own supply lines and disrupt Turkish trade in the area.
In January 1769, a 70-thousand man Turkish-Tatar army led by Crimean Khan Qırım Giray invaded the lands of central Ukraine. Crimean Tatars, Turks, and Nogais ravaged New Serbia, taking a significant number of slaves.
On September 17, 1769, the Russians began their initial campaign over the Dniester into Moldavia. The elite Ottoman janissaries took heavy casualties from the Russians at Khotyn but managed to hold on; the remainder of the Ottoman army panicked and abandoned the field, and the Russians claimed the fortress. With the Ottomans in disarray the Russians took the capital of Moldavia (Jassy) on October 7. They continued the advance south into Wallachia, occupying its capital Bucharest on November 17. From the capital of Bucharest, the Russians fanned out through the principality, only later being challenged by Grand Vizier Mehmed Emin Pasha at Kagul on Aug 1, 1770. The Russians routed the Grand Vizier's forces and allegedly one-third of the Ottoman troops drowned in the Danube trying to escape.
By now, Russia had some troops spread out north of the Caucasus. In 1769, as a diversion, the Russians sent Gottlieb Heinrich Totleben with a small expeditionary force south into Georgia. The Georgians defeated an Ottoman army at Aspindza in 1770. The Siege of Poti on the Black Sea coast by a joint Russo-Georgian force in 1771 failed and Russian troops were withdrawn in the spring of 1772. It was the first time Russian troops had crossed the Caucasus. On the steppes north of the mountains, the later-famous Matvei Platov and 2,000 men fought 25,000 Turks and Crimeans. The Cossack village of Naur was defended against 8,000 Turks and tribesmen.
Russian Mediterranean expedition
During the war, a Russian fleet, under Count Alexei Grigoryevich Orlov, entered the Mediterranean Sea for the first time in history. This First Archipelago Expedition of 1769 to 1774, with ships drawn from the Baltic Fleet, aimed to draw Ottoman naval forces out from the Black Sea. In Ottoman Greece, Orlov's arrival sparked a Maniot revolt against the Ottoman authorities. However, the Ottoman vizier Muhsinzade Mehmed Pasha (in office 1765 to 1768 and 1771 to 1774) called on the provincial notables (ayans) of Ottoman Albania to mobilize irregular troops, which he used to crush the revolt in 1771.