Gustav II Adolf (9/19 December 1594 – 6/16 November 1632, O.S./N.S.), widely known in English by his Latinised name Gustavus Adolphus or as Gustav II Adolph, was the King of Sweden from 1611 to 1632 who is credited for the founding of Sweden as a great power (Swedish: Stormaktstiden). He led Sweden to military supremacy during the Thirty Years' War, helping to determine the political as well as the religious balance of power in Europe. He was formally and posthumously given the name Gustavus Adolphus the Great (Swedish: Gustav Adolf den store, Latin: Gustavus Adolphus Magnus) by the Riksdag of the Estates in 1634.
In an era characterized by almost endless warfare, Gustavus Adolphus inherited three simultaneous and ongoing wars of his father at the age of sixteen. Two of these were border wars with Russia and Denmark, and a more personal war (at least for his father) with Gustavus' first cousin, King Sigismund III Vasa of Poland. Of these three wars that were passed onto his rule, the Danish war was the most acute one.
During his reign, Sweden rose from the status of a Baltic Sea basin regional power to one of the great powers of Europe and a model of early modern era government. Gustavus Adolphus is famously known as the "father of modern warfare", or the first great modern general. Under his tutelage, Sweden and the Protestant cause developed a number of excellent commanders, such as Lennart Torstensson, who would go on to defeat Sweden's enemies and expand the boundaries and the power of the empire long after Gustavus Adolphus' death in battle. Spoils of Adolphus' enemies meant he became a successful bookraider in Europe, specifically with Jesuit Collections.
Called "The Golden King" and "The Lion of the North", he made Sweden one of the great powers of Europe, in part by reforming the administrative structure. For example, he began parish registration of the population, so that the central government could more efficiently tax and conscript the people. Historian Christer Jorgensen argues that his achievement in the field of economic reform, trade, modernization, and the creation of the modern bureaucratic autocracy was as great as his exploits on the battlefields. His domestic reforms, which transformed a backward, almost medieval economy and society, were in fact not only the foundations for his victories in Germany, but also absolutely crucial for the creation and survival of the Swedish Empire.
He is widely commemorated by Protestants in Europe as the main defender of their cause during the Thirty Years' War, with multiple churches, foundations and other undertakings named after him, including the Gustav-Adolf-Werk.
Gustavus Adolphus was born in Stockholm as the oldest son of Duke Charles of the Vasa dynasty and his second wife, Christina of Holstein-Gottorp. At the time, the King of Sweden was Gustavus Adolphus' cousin Sigismund. The staunch Protestant Duke Charles forced the Catholic Sigismund to let go of the throne of Sweden in 1599, a part of the preliminary religious strife before the Thirty Years' War, and reigned as regent before taking the throne as Charles IX of Sweden in 1604. Crown Prince Gustav Adolph had Gagnef-Floda in Dalecarlia as a duchy from 1610. Upon his father's death in October 1611, a sixteen-year-old Gustavus inherited the throne, being declared of age and able to reign himself at seventeen as of 16 December. He also inherited an ongoing succession of occasionally belligerent dynastic disputes with his Polish cousin. Sigismund III wanted to regain the throne of Sweden and tried to force Gustavus Adolphus to renounce the title.
In a round of this dynastic dispute, Gustavus invaded Livonia when he was 31, beginning the Polish–Swedish War (1626–29). He intervened on behalf of the Lutherans in Germany, who opened the gates to their cities to him. His reign became famous from his actions a few years later when in June 1630 he landed in Germany, marking the Swedish Intervention in the Thirty Years' War. Gustavus intervened on the anti-Imperial side, which at the time was losing to the Holy Roman Empire and its Catholic allies; the Swedish forces would quickly reverse that situation.
Gustavus was married to Maria Eleonora of Brandenburg,[a] the daughter of John Sigismund, Elector of Brandenburg, and chose the Prussian city of Elbing as the base for his operations in Germany. He died in the Battle of Lützen in 1632. His early death was a great loss to the Lutheran side. This resulted in large parts of Germany and other countries, which had been conquered for Lutheranism, to be reconquered for Catholicism (via the Counter-Reformation). His involvement in the Thirty Years' War gave rise to the saying that he was the incarnation of "the Lion of the North", or as he is called in German "Der Löwe aus Mitternacht" (Literally: "The Lion of Midnight").