The Battle of Poltava (8 July 1709) was the decisive and largest battle of the Great Northern War. A Russian army under the command of Tsar Peter I defeated a Swedish army, under the command of Carl Gustaf Rehnskiöld. The battle put an end to the status of the Swedish Empire as a European great power, as well as its eastbound expansion, and marked the beginning of Russian influence in Northern Europe.
During the course of six years in the initial stages of the war, King Charles XII and the Swedish Empire had defeated almost all participants in the anti-Swedish coalition, which initially consisted of the Polish-Lithuanian Commonwealth, Denmark-Norway and the Tsardom of Russia. The latter under Tsar Peter I's rule was the only one still undefeated. Charles XII therefore chose to invade Russia in the autumn of 1707 and march towards Moscow with a large Swedish army. However, the campaign was complicated by harsh weather conditions and by the Russians applying scorched earth tactics and surprise attacks, which forced Charles XII to interrupt his march on Moscow and instead march south to establish winter quarters with the help of Ivan Mazepa, hetman of the Cossack Hetmanate Zaporizhian Host.
After the extremely harsh Great Frost of 1708–1709, the weakened Swedish army resumed operations in the spring of 1709 and began a siege of the fortress of Poltava, an important trading center and military depot on the Vorskla. Meanwhile, a numerically superior Russian army of 75,000–80,000 men commanded by Peter, advanced to Poltava in order to relieve the siege. The two armies clashed, and ended with the Swedes being defeated and fleeing the battlefield. Charles and Mazepa retreated with 1,500 men south to the river Dnieper, which they crossed, thus managing to escape the Russians and established themselves in the Ottoman Empire. The rest of the army was forced to surrender to the Russians at the village of Perevolochna on 11 July 1709.
The Battle of Poltava, as well as the subsequent capitulation, ended in a decisive victory for Peter I and became the greatest military catastrophe in Swedish history. It marked a turning point in the continuation of the war in favour of the anti-Swedish coalition, which as a result of the battle was revived and with renewed vigor attacked the weakened Swedish Empire on several fronts. The battle thus marked the end of Sweden's time as the dominant power in Northern Europe, a position which after the war was taken over by the Russian Empire. The battle is therefore of crucial importance in the history of Sweden as well as Russia and Ukraine.
Background
Charles XII had led Swedish forces to early victories in North Zealand (Summer 1700) and in the Battle of Narva in November 1700. However, it took six years for him to defeat Augustus II of Saxony-Poland. Peter I withdrew from Poland in the spring of 1706, and offered to return the Baltic provinces of Sweden that Russia had occupied since 1703 - except for Ingria where Peter had already started to build his intended new capital of St. Petersburg - but Charles refused. Peter subsequently adopted a scorched-earth policy in order to deprive the Swedish forces of supplies.
Charles ordered a final attack on the Russian heartland with a possible assault on Moscow from his campaign base in Poland. The Swedish army of almost 44,000 men left Saxony on 22 August 1707 and marched slowly eastwards. Charles took the field in November after waiting for reinforcements to arrive. Continuing east, he crossed the Vistula River on 25 December 1707, then continued through a hostile Masuria and took Grodno on 26 January 1708 after Russian troops had abandoned the city. At the time the Russians had been occupied with a large rebellion of Don Cossacks, known as the Bulavin Rebellion (1707–1708). This revolt was contained in part by the forces of the Cossack Hetmanate led by Hetman Ivan Mazepa. The Swedes continued to the area around Smorgon and Minsk, where the army went into winter quarters. Charles left 8,000 dragoons under Major General Ernst Detlof von Krassow in western Poland.
Poor weather and road conditions kept the Swedish troops in winter quarters until June 1708. In July the Swedes defeated Marshal Boris Sheremetyev's forces at the Battle of Holowczyn and advanced to the Dnieper River. During the spring General Lewenhaupt in Courland had been ordered to gather supplies and march his army of about 12,000 men to join Charles' forces. However, his departure from Mitau was delayed until late June and consequently he only joined Charles' forces on 11 October.