Gustav II Adolf, (9 December 1594 – 6 November 1632 (O.S.) or Gustav II Adolphus, widely known in English by the Latinized name Gustavus Adolphus and variously in historical writings sometimes as simply just Gustavus, or Gustavus the Great, or Gustav Adolf the Great, (Gustav Adolf den store, from the special distinction passed by the Swedish Parliament in 1634), was founder of the Swedish Empire (or Stormaktstiden — "the era of great power") at the beginning of what is widely regarded as the Golden Age of Sweden.
In the era, which was characterized by nearly endless warfare, he led his armies as King of Sweden—from 1611, as a seventeen year old, until his death in battle while leading a charge during 1632 in the bloody Thirty Years' war—as Sweden rose from the status as a mere regional power and run of the mill kingdom to one of the great powers of Europe and a model of early modern era government. Sweden expanded to become the third biggest nation in Europe after Russia and Spain within only a few years during his reign. Some have called him the father of modern warfare, or the first great modern general. It is indisputable that under his tutelage, Sweden and the Protestant cause developed a host of good generals—who continued to expand the empires' strength and influence long after his death in battle.
He is, and was even during his own time (The Italians referred to him as "The Golden King" and others as "The Lion of the North"), widely regarded as the archetype of what a king should be and one of the few European kings and sovereign princes during the seventeenth century worthy of the office. He was, unquestionably, one of the greatest military generals in all of history, and his battles were studied assiduously by later great military figures such as Napoleon; Arthur Wellesley, 1st Duke of Wellington; Carl von Clausewitz; and Patton, as they are still taught in military science courses today. Gustavus Adolphus is today immortalised in two city squares, one in Stockholm and the other in Gothenburg, both named in Swedish Gustav Adolfs torg.
In a round of this dynastic dispute, he invaded Livonia when he was , beginning the Polish-Swedish War (1625–1629). He intervened on behalf of the Lutherans in Prussia, who opened the gates to their cities. His reign became famous from his actions a few years later when in June 1630 he landed in Germany, continuing Sweden's involvement in the ongoing 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.
He was married to Maria Eleonora of Brandenburg, 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, it prolonged the war for many years. It resulted in large parts of Germany and other countries, who for a large part had become Lutheran in faith,to be forced into Catholicism (via Counter-Reformation). His involvement in the Thirty Years' War gave rise to the old prophecy that he was the incarnation of "the Lion of the North", or as it is called in German "Der Löwe von Mitternacht" (Literally: "The Lion from Midnight").
Gustavus Adolphus was the main figure responsible for the success of Sweden during the Thirty Years' War and led his nation to great prestige. As a general, Gustavus Adolphus is famous for employing mobile artillery on the battlefield, as well as very aggressive tactics, where attack was stressed over defense, and mobility and cavalry initiative were emphasized.
Among other innovations, he installed an early form of combined arms in his formations where the cavalry could attack from the safety of a infantry line reinforced by canon, and retire again within to regroup after their foray. He adopted much shallower infantry formations than were common in the pike and shot armies of the era, with formations typically fighting in 5 or 6 ranks, occasionally supported at some distance by another such formation—the gaps being the provinces of the artillery and cavalry as noted above. His artillery were themselves different—he would not let himself be hindered by cumbersome heavy cannon, but instead over a course of experimentation settled on smaller more maneuverable weapons, in effect fielding the first light field artillery in history in any significant ratios.
These grouped in batteries, supported his more linearly deployed formations, the whole in his armies replaced the cumbersome and unmaneuverable traditional deep squares up to 50 ranks deep (Spanish Tercios), used in other pike and shot armies of the day. In consequence, his forces could redeploy and reconfigure extremely rapidly confounding his enemies.
His armies were very well trained for the day, so that his musketeers were widely known for their firing accuracy and reload speed: three times faster than any contemporary rivals. Carl von Clausewitz and Napoleon Bonaparte considered him one of the greatest generals of all time— a sentiment agreed to by Patton and others. He was also renowned for the consistency of purpose and the amity of his troops—no one part of his armies were considered better or received preferred treatment as was common in other armies where the cavalry were the elite, followed by the artillerist, and both disdained the lowly infantry. In a Gustavus' army, the units were extensively cross trained. Both cavalry and infantry could service the artillery— as his heavy cavalry did when turning captured artillery on the opposing Catholic Tercios at First Breitenfeld; pikemen could shoot—if not as accurately as those designated muskateers so a valuable firearm could be kept in the firing line, and his infantrymen and gunners were taught to ride, if needed. Napoleon thought highly of the achievement, and copied the tactics.
In March 1632, Gustavus Adolphus invaded Bavaria. He forced the withdrawal of his Catholic opponents at the Battle of Rain. This would mark the high point of the campaign. In the summer of that year, he sought a political solution that would preserve the existing structure of states in Germany, while guaranteeing the security of its Protestants. But achieving these objectives depended on his continued success on the battlefield.
Gustavus Adolphus was killed at the Battle of Lützen, when, at a crucial point in the battle, he became separated from his troops while leading a cavalry charge into a dense smog of mist and gunpowder smoke. After his death, his wife initially kept his body, and later his heart, in her castle for over a year. His remains (including his heart) now rest in Riddarholmskyrkan in Stockholm.
In February 1633, following the death of the king, the Swedish Riksdag of the Estates decided that his name would be styled Gustav Adolf the Great (or Gustaf Adolf den Store in Swedish). No such honor has been bestowed on any other Swedish monarch since.
The crown of Sweden was inherited in the Vasa family, and from Charles IX's time excluded those Vasa princes who had been traitors or descended from deposed monarchs. Gustavus Adolphus' younger brother had died years before, and therefore there were only female heirs left. Maria Eleonora and the king's ministers took over the government on behalf of Gustavus Adolphus' underage daughter Christina upon her father's death. He left one other known child, his illegitimate son Gustav, Count of Vasaborg.
In his book "Ofredsår" ("Years of Warfare"), the Swedish historian and author Peter Englund argues that there was probably no single all-important reason for the king's decision to go to war. Instead, it was likely a combination of religious, security, as well as economic considerations.
A history of Gustavus Adolphus' wars was written by Johann Philipp Abelin.
Gustavus Adolphus Day is celebrated in Sweden each year on November 6. On this day only a special pastry, with a chocolate or marzipan medallion of the king, is sold. The day is also an official flag day in the Swedish calendar. In Finland, the day is celebrated as svenska dagen or ruotsalaisuuden päivä, "Swedishness Day", and is a customary flag day. In both countries, November 6 is the name day for Gustav Adolf, one of the few exceptional name days in the year.