Warmatrix

Portrait of Gustavus Adolphus by Jacob Hoefnagel

Gustavus Adolphus (Latin name) alias Gustav II Adolf (Swedish name) was king of Sweden from 1611 CE to 1632 CE. Besides being king, he was also a significant military innovator, though his role in this regard is often overrated.
Gustavus Adolphus was born in 1594 CE. In the early 17th century CE, while he was still a youth, Sweden converted to protestantism and soon got into conflict with its neighbors. Besides religious motives, economical, military and political factors were also at work. This was the start of the "Stormaktstiden", the time of Sweden as a great power. When Gustavus Adolphus inherited the throne in 1611 CE, the country was embroiled in no less than three wars, against Denmark, Russia and Poland.
The Kalmar War against Denmark was fought over trading rights through the Denmark Sound. Gustavus Adolphus knew that the war was lost and sought peace, yet it took three years to wear the other side out. The young king nearly drowned at the Battle of Vittsjö. Sweden won trading rights, but had to pay a large indemnity for years to Denmark, which also gained a overland trading route and two forts.
The Ingrian War against Russia against Russia saw the Swedes push east as far as Novgorod and Ingria, though the thinly populated lands offered little. In 1617 CE a peace was concluded that denied Russia access to the Baltic Sea for about a century. During this period Gustavus Adolphus reformed the state, creating a balance between the throne and the Riksdag, the parliament. Immigration was encouraged; industry and education improved. The reforms increased tax revenue, which was used to fund his army. The king proved an excellent debater who, despite the modernization of the state, also enhanced his personal power.
The third war, with Poland, was a series of conflicts and temporary peace agreements that lasted to 1629 CE. Sweden gained territory in Livonia, including the city of Riga, making it master of nearly the entire Baltic area. It was during this time that Gustavus Adolphus ordered the construction of the Vasa, a warship so large that it sank less than a mile from the harbor on its first voyage, creating Sweden's most famous shipwreck. Also he suffered a gun wound that left two fingers of his right hand paralyzed and prohibited him from wearing heavy armor. In the end this would prove his undoing.
In all the wars the king took an active part as commander and gained valuable experience. He used this to reorganize the Swedish army. Line infantry tactics were perfected; cavalry was equipped with guns and he created mobile field artillery. Some value these as great innovations; others state that the king was only improving on earlier developments.
In 1630 CE, with the three earlier wars concluded and Denmark defeated by Germany in the year before, Sweden was free to try its might elsewhere. Gustavus Adolphus joined the protestant cause in the Thirty Years' War, though his motives seem to have concentrated on a desire to expand his country's economy and power. He landed in Pomerania with enough troops and money to capture the region, yet too little to sustain further conquests. Nonetheless he scored a major victory at the (First) Battle of Breitenfeld in the next year, boosting his prestige and his army's morale.
In 1632 CE there were several more battles, while the Swedes steadily pushed south. Gradually, Gustavus Adolphus saw his task to be to unite the German principalities, with himself at their head. He might even have contemplated becoming German emperor. In November the Swedish army won the hard-fought Battle of Lützen, one of the most decisive of the war. But it was also Gustavus Adolphus' last; he died in the thick of the fighting.
The Thirty Years' War made Sweden one of the great powers in Europe for a about a century. But the the drain on the treasury and the population was high. Gustavus Adolphus' most lasting achievements were the preservation of protestantism in Germany and the modernization of his own country.