The outbreak of the war was preceded by the alliance (1699) of Peter I, Frederick IV of Denmark, and Augustus II of Poland (who was also elector of Saxony) against Charles XII, whose youth and inexperience they hoped would make him an easy victim. The war began with the invasion of Swedish Livonia by the Poles and of ducal Schleswig (which had rebelled against Danish rule with Swedish support) by the Danes. The bold and unexpected landing of Charles XII in Sjæland threatened Copenhagen and forced Denmark out of the war (1700).
Charles then turned his attention to the east; late in 1700 he routed a much superior Russian force at Narva and relieved Riga, which the Poles were besieging. Invading Poland, Charles took Warsaw and Cracow (1702), secured the election of Stanislaus I as king of Poland (1704), followed Augustus into Saxony, and forced him to break his alliance with Russia and to recognize Stanislaus as king by the Treaty of Altranstädt (1706). While Charles was victorious in Poland, however, Peter I occupied Ingermanland and part of Livonia.
Resuming (1707) his campaign against Russia, Charles invaded Ukraine, where Mazepa had promised to foment an anti-Russian uprising. Mazepa's project failed, and the Swedes, cut off from reinforcements and in need of a stronghold, laid siege to the fortress of Poltava. There a superior Russian army utterly defeated (1709) the Swedes, and Charles retired with a handful of men to Bessarabia, on Turkish territory.
His intrigues at Constantinople induced the sultan to declare war on Russia (1710). Peter I, allied with Prince Constantine Brancovan of Walachia and Prince Demetrius Cantemir of Moldavia, invaded these two vassal principalities of Turkey and entered Jassy, but he soon found himself outnumbered and consented (1711) to the disadvantageous Treaty of the Pruth (see Russo-Turkish Wars).
While Charles was stubbornly refusing to leave Turkey, Augustus II took advantage of his absence; he invaded (1709) Poland and expelled Stanislaus I, while Peter I completed the conquest of Swedish Livonia, Ingermanland, and Karelia. Frederick IV of Denmark also resumed the war, seized ducal Schleswig, and conquered the Swedish duchies of Bremen and Verden in Germany, which he sold to Hanover on condition that Hanover join in the war against Sweden. Swedish Pomerania was taken by the Poles, and Prussia, fishing in troubled waters, seized Stettin. In 1714, Charles XII returned to Sweden. Undaunted by the coalition of Russia, Denmark, Poland, Saxony, Hanover, and Prussia, he began military operations in Norway (then ruled by Denmark), where he was fatally shot in 1718.
Charles's successor, Ulrica Leonora, and her husband, Frederick I of Sweden, began peace negotiations. Peace was made with all enemies but Russia in the treaties of Stockholm and Frederiksborg (1719-20). Augustus II of Poland restored all his conquests; Hanover retained the duchies of Bremen and Verden, but paid a large indemnity; Prussia received Stettin and part of W Pomerania, the rest reverting to Sweden; Denmark restored its conquests for a payment, but Sweden permitted the union of ducal Schleswig with royal Schleswig under the Danish crown and renounced Swedish exemption from customs duties in the Sound. By the Treaty of Nystad with Russia (1721) Sweden ceded Livonia (including Estonia), part of Karelia, and Ingermanland, but retained Finland. The lasting results of the Northern War were the waning of Swedish power, the establishment of Russia as a major power of Europe, with its "window" on the Baltic Sea, and the decay of Poland.
See L. Cooper, Many Roads to Moscow (1968).
The Great Northern War (1700-21) was fought between Russia and Sweden for supremacy in the Baltic Sea. Initially, Russia joined the coalition in the war with Denmark and Saxony – composed of the so-called Northern Alliance, but after the outbreak of hostilities the Union collapsed, and was rebuilt in 1709. At various stages of the war other participants attended: on the side of Russia – Hanover, Holland, Prussia, the Polish-Lithuanian Commonwealth; on the side of Sweden – the Ottoman Empire, Zaporozhian Cossacks, and others. The war ended with the defeat of Sweden in 1721, leaving Russia dominant in the Baltic Sea and a major player in European politics. The war began as a coordinated attack on Sweden by the coalition in 1700 and ended in 1721 with the Treaty of Nystad and the Stockholm treaties.
The foreign interventions during the Time of Troubles resulted in Sweden's gains in the Treaty of Stolbovo (1617). The treaty deprived Russia of direct access to the Baltic Sea, meaning that the Russians were not in a position to challenge the Swedish regional hegemony. Russian fortunes reversed during the later half of the 17th century, notably with the rise to power of Peter the Great, who looked to address the earlier losses and re-establish a Baltic presence. In the late 1690s, the adventurer Johann Patkul managed to ally Russia with Denmark and Saxony by the Treaty of Preobrazhenskoye and in 1700 the three powers attacked.
Though able to mobilize 170,000 men, Russia was not able to put all in action at the same place. Furthermore, the Russian mobilization system was ineffective, and the expansive nation had to be defended everywhere—garrisons had to be supported and the war paid for. A great mobilization over vast territories would have been unrealistic. Peter the Great aimed to have an army with the same morale as the Swedish.
The Danes added 20,000 in their invasion against Holstein-Gottorp and several more against other fronts. Poland and Saxony together could mobilize at least 100,000 men.
After the dissipation of the first coalition through the peace of Travendal and the victory at Narva, the Swedish chancellor, Benedict Oxenstjerna, rightly regarded the universal bidding for the favor of Sweden by France and the maritime powers, then on the eve of the War of the Spanish Succession, as a golden opportunity of ending the war and making Charles the arbiter of Europe.
At that time, the representatives of Poland-Lithuania (which considered itself neutral despite its king's active participation in the anti-Swedish coalition) offered to serve as mediators between the Swedish king and Augustus. But Charles, intent on dethroning Augustus of Saxony from the Polish throne, attacked Poland, therefore ending the official neutrality of Poland-Lithuania. Five years later, on September 24, 1706, he concluded the Polish War through the treaty of Altranstadt, but, this treaty brought no advantage to Sweden, not even compensation for the expenses of six years of warfare. But he did attain his goal of dethroning August II and putting his ally Stanisław on the throne. Since he believed that Poles in general were not responsible he didn't do anything more. That has been regarded as a mistake since it became very easy for August II to retake the throne.
Even now Charles, by a stroke of the pen, could have recovered nearly everything he had lost. In 1707, Peter was ready to retrocede everything except Saint Petersburg and the line of the Neva, and again Charles preferred risking the whole to saving the greater part of his Baltic possessions. The year following, he invaded Russia, but was frustrated in Smolensk by Generalissimo Menshikov and headed to Ukraine for the winter. However, the abilities of his force were sapped by the cold weather and Peter's use of scorched earth tactics. When the campaign started again in the spring of 1709, a third of his force had been lost and he was crushingly defeated by a larger and better-fed Russian force under Peter in the Battle of Poltava, fleeing to the Ottoman Empire and spending five years in exile. Peter's victory shook all European courts. In just one day, Russia emerged as a major European power.
This shattering defeat did not end the war, although it decided it. Denmark and Saxony joined the war again and Augustus the Strong, through the crafty politics of Boris Kurakin, regained the Polish throne. Peter continued his campaigns in the Baltics, and eventually he built up a powerful navy. In 1710 the Russians captured Tallinn and Viipuri. In 1714, Peter's galley navy managed to capture a small detachment of the Swedish navy in the first Russian naval victory near Hanko peninsula.
The Russian army occupied Finland mostly in 1713-1714, Viipuri had been captured already in 1710. The last stand of the Finnish troops was in the battle of Napue in early 1714 in Isokyrö, Ostrobothnia. The occupation period of Finland in 1714-1721 is known as the Greater Wrath (isoviha). During the bloody occupation period thousands of Finns were killed or deported to Russia.
Over the next few years little changed, but a series of raids on Sweden itself demonstrated that there was little fight left, and soon Prussia, Hanover, and many smaller German states entered the war in the hope of gaining territory when peace was made. Eventually a series of massive seaborne invasions by combined Danish and Russian navies of the Swedish homeland forced the issue.
The war was finally concluded by the Treaty of Nystad between Russia and Sweden in Uusikaupunki in 1721. Sweden had lost almost all of its "overseas" holdings gained in the 17th century, and ceased to be a major power. Russia gained its Baltic territories, and became the greatest power in Eastern Europe. Prussia and Hanover, which made peace agreements with Sweden before Russia, gained territory from Sweden's German possessions. Sweden's dissatisfaction with the result would lead to its fruitless attempts at recovering the lost territories, such as Hats' Russian War, and Gustav III's Russian War.