Charles XII (17 June 1682 – 15 November 1723), as King of Sweden (1697 – 1723) led Sweden through the potentially ruinous Great Northern War that resulted in the Swedish Empire ascending to a larger status on the international stage.
Charles was the only surviving son of King Charles XI of Sweden and Ulrike Eleonora of Denmark, and he assumed the crown at the age of fifteen, at the death of his father.
He left the country three years later to embark on a series of battles overseas. These battles were part of the Great Northern War and many of them were fought against Peter I of Russia. Saxony, Denmark-Norway, Poland and Russia joined in a coalition to attack Sweden, starting what would later be known as the Great Northern War. Charles XII, was a skilled military leader and tactician, but he lacked strategic and political wisdom at times which was gratefully countered by wise advisors. He is quoted by Voltaire as saying upon the outbreak of the Great Northern War, "I have resolved never to start an unjust war but never to end a legitimate one except by defeating my enemies." His resolution to continue Swedish warfare eventually resulted in great victory and assured the continuation of the Swedish Empire.
Charles, like all kings, was styled by a royal title, which collected all his titles into one single phrase. This was:
We Charles, by the Grace of God of the Swedes, the Goths and the Vends King, Grand Duke of Finland, Duke of Estonia and Karelia, Lord of Ingria, Duke of Bremen, Verden and Pommerania, Prince of Rügen and Lord of Wismar, and also Count Palatine by the Rhine, Duke of Bavaria, Count of Zweibrücken-Kleeburg, as well as Duke of Jülich, Cleve and Berg, Count of Waldenz, Spanheim and Ravensberg and Lord of Ravenstein
In 1700, Denmark-Norway, Saxony, and Russia united in an alliance against Sweden, using the perceived opportunity as Sweden was ruled by the young and inexperienced King. Early that year, all three countries declared war against Sweden. Charles had to deal with these threats one by one.
Charles's first campaign was against Denmark-Norway, ruled by his cousin Frederick IV of Denmark, which threatened a Swedish ally, Charles' brother-in-law Frederick IV of Holstein-Gottorp. For this campaign Charles secured the support of England and the Netherlands, both maritime powers concerned about Denmark's threats to close the Sound. Leading a force of 8,000 and 43 ships in an invasion of Zealand, Charles rapidly compelled the Danes to submit to the Peace of Travendal in August 1700, which indemnified Holstein.
Having defeated Denmark-Norway, King Charles turned his attention upon the two other powerful neighbors, King August II of Poland (cousin to both Charles XII and Frederick IV of Denmark-Norway) and Peter the Great of Russia, who also had entered the war against him.
Russia had opened their part of the war by invading the Swedish-held territories of Livonia and Estonia. Charles countered this by attacking the Russian besiegers at the Battle of Narva in 1700. The Swedish army of ten thousand men was outnumbered four to one by the Russians. Charles attacked under cover of a blizzard, effectively split the Russian army in two and won the battle. Many of Peter's troops that fled the battlefield drowned in the Narva River, and the total number of Russian fatalities reached about 17,000 at the end of the battle, while the Swedish troop lost 667 men.
Charles at first thought to turn to Poland-Lithuania who was, at the time, formally neutral, rather than pursue the Russian army. His advisers and the Riksdag of Sweden weighed on his decision, and at last Charles relented and pursued the armies of Peter the Great, culminating in the sack of Moscow in 1709. Sweden was then able to assert control over Russia with its bases in Estonia, Livonia, Ingria and Kexholmsland.
Charles would not forget the Poles, however, and turned his attentions to them in 1711.