During the Russo-Turkish war of 1768–1774, Catherine the Great, Tsarina of Russia, concocted a plan for driving the Ottomans out of the territory held by the former Byzantine Empire and placing her grandson Constantine on the imperial throne of Constantinople.
More than three centuries after the fall of the Byzantine Empire, the Ottomans were defending themselves against another orthodox Christian power: Tsarist Russia. The Russian forces were largely victorious in the war and they were in a position to annex Ottoman territory in Europe and the Middle East. But the complexities of European politics of that time were such that the West European powers feared that the balance of power in Europe could tilt permanently in Russia’s favor if they allowed the Russians to dominate a significant part of Ottoman territory. Austria and other West European states intervened diplomatically to place a limit on the territorial gains that the Russians could expect from their victory.
The Ottomans and the Russians signed the Treaty of Küçük Kaynarca in 1774. Russia returned the territories of Wallachia and Moldavia to the Ottomans. Catherine negotiated and got the guardianship of the Orthodox Christian holy sites and the right to protect Orthodox Christians throughout the Ottoman Empire—this provision ensured that the Russians had a ready-made excuse to interfere in Ottoman territory whenever they thought that the time was ripe. A second war between the Russian and Ottoman empires was inevitable.
In 1783, Russia annexed Crimea and Kabardia. In May and June 1787, Catherine and her new ally, the Holy Roman Emperor Joseph II, held a triumphal procession in New Russia and the annexed Crimea. The Ottomans saw the triumphal procession as a violation of their territory—they ordered the Russians to evacuate Crimea. In August 1787, the Ottomans declared a war on Russia with the aim of reversing the losses of the earlier Russo-Turkish war. While this war was being fought, the Ottomans became involved in another war with Austria in 1788. Both wars were fought concomitantly till 1792. Caught between two wars, the Ottoman situation became militarily hopeless. Their logistics collapsed, and they were forced to negotiate.
The Treaty of Jassy, signed between Russia and the Ottoman Empire in 1792, established Russian dominance in the Black Sea region. The Ottoman aim of reclaiming Crimea had failed. If the West European powers and the Orthodox Russian Empire had not been distracted by the eruption of the French Revolution in 1789, the fate of the Ottoman Empire could have been much worse during the second Russo-Turkish War.