Ottoman Empire in 1736, prompted by raids on Ukraine by Crimean Tatars and the military campaign of the Crimean khan in the Caucasus. In May 1736, the Russian army launched an invasion of the Crimean peninsula and burned the capital of the Crimean Khanate Bakhchisarai. On June 19, the Russian Don army under the command of General Peter Lacy captured Azov. In July 1737, the Münnich army took by storm the Ottoman fortress of Ochakov. The Lacy army (now 40,000 strong) marched into the Crimea the same month, inflicting a number of defeats on the army of the Crimean khan and capturing Karasubazar. Lacy and his soldiers had to leave the Crimea, however, due to lack of supplies. Austria entered the war against Turkey in July 1737 but was defeated a number of times. In August, Russia, Austria and Turkey began negotiations in Nemirov, which would turn out to be fruitless. There were no significant military operations in 1738. The Russian army had to leave Ochakov and Kinburn due to a plague outbreak. In 1739, the Münnich army crossed the Dnieper, defeated the Ottoman Empire at Stavuchany, and occupied the fortress of Khotin and Iaşi. However, Austria was defeated by the Ottoman Empire once again and signed a separate peace treaty on August 21. This, coupled with the imminent threat of Swedish invasion, forced Russia to sign the Treaty of Belgrade with Turkey on September 18, ending the war. Gradual defeat of the Ottoman Empire (1768–1878) Catherine the Great Following a border incident at Balta, Sultan Mustafa III declared war on Russia on September 25, 1768. The Turks formed an alliance with the Polish opposition forces of the Bar Confederation, while Russia was supported by Great Britain, which offered naval advisers to the Russian navy. The Polish opposition was defeated by Alexander Suvorov, who was then transferred to the Ottoman theatre of operations, where in 1773 and 1774 he won several minor and major battles following the previous grand successes of the Russian Field-Marshal Pyotr Rumyantsev at Larga and Kagul. Naval operations of the Russian Baltic Fleet in the Mediterranean yielded victories under the command of Aleksei Orlov. In 1771, Egypt and Syria rebelled against the Ottoman rule, while the Russian fleet totally destroyed the Ottoman Navy at the battle of Chesma. On July 21, 1774, the Ottoman Empire signed the Treaty of Küçük Kaynarca, which formally granted independence to