The Russo-Ottoman War of 1710—1711, also known as the Pruth River Campaign, was a brief military conflict between the Tsardom of Russia and the Ottoman Empire. The main battle took place during 18-22 July 1711 in the basin of the Pruth river near Stănilești (Stanilesti) after Tsar Peter I entered the Ottoman vassal Principality of Moldavia, following the Ottoman Empire’s declaration of war on Russia. The ill-prepared 38,000 Russians with 5,000 Moldavians, found themselves surrounded by the Ottoman Army under Grand Vizier Baltaci Mehmet Pasha. After three days of fighting and heavy casualties the Tsar and his armies were allowed to withdraw after agreeing to abandon the fortress of Azov and its surrounding territory. The Ottoman victory led to the Treaty of the Pruth which was confirmed by the Treaty of Adrianople. Background The Russo-Ottoman War of 1710-1711 broke out as a result of the Great Northern War, which pitted the Swedish Empire of King Charles XII of Sweden against the Russian Empire of Tsar Peter I. Charles invaded Russian-ruled Ukraine in 1708, but suffered a decisive defeat at the Battle of Poltava in the summer of 1709. He and his retinue fled to the Ottoman fortress of Bender, in the Ottoman vassal principality of Moldavia. Ottoman Sultan Ahmed III declined incessant Russian demands for Charles's eviction, prompting Tsar Peter I of Russia to attack the Ottoman Empire, which in its turn declared war on Russia on 20 November 1710. Concurrently with these events, the ruler (hospodar) Dimitrie Cantemir of Moldavia and Tsar Peter signed the Treaty of Lutsk (13 April 1711), by which Moldavia pledged to support Russia in its war against the Ottomans with troops and by allowing the Russian army to cross its territory and place garrisons in Moldavian fortresses. In the summer of 1711, Peter led his army into Moldavia and united it with Cantemir's forces near the Moldavian capital Iași; they then advanced southwards along the Prut River. They aimed to cross the Danube, which marked the border between Moldavia and Ottoman territory proper. Meanwhile, the Ottoman government mobilized their own army, which outnumbered the Russo-Moldavian troops significantly (according to one estimate, by a ratio of six to one). Under the command of Ottoman grand vizier Baltacı Mehmet Pasha, it advanced north to confront the Russians in June 1711. Military actions Peter assigned Field Marshal Boris Sheremetev to prevent the Ottoman army from crossing the