Gustav II Adolf of Sweden (9 December 1594 – 6 November 1632, O.S.

), widely known in English by his Latinized name Gustavus Adolphus and variously in historical writings also as Gustavus, or Gustavus the Great, or Gustav Adolph the Great (Swedish: Gustav Adolf den store, a formal distinction passed by the Swedish Parliament in 1634), is founder of the Swedish Empire (or Stormaktstiden – "the era of great power") at the beginning of the Golden Age of Sweden.

He is the King of Sweden (1611–1632) who leads the nation to military supremacy during the Thirty Years War, helping to determine the political as well as the religious balance of power in Europe.

His most notable military victory is the Battle of Breitenfeld (1631).

With a superb military machine with good weapons, excellent training, and effective field artillery, all backed by a highly efficient government back home that pays the bills on time, Gustavus Adolphus is poised to make himself a major European leader, but he is killed in battle in 1632.

He is assisted by Axel Oxenstierna (1583–1654), leader of the nobles, who also acts as regent after his death.

In this age, which is characterized by nearly endless warfare, he leads his armies as king from 1611 (at age 17) until his death in battle while leading a charge during 1632 —as Sweden rises 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 expands 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.

Under his tutelage, Sweden and the Protestant cause develop a number of excellent commanders, such as Lennart Torstensson, who will go on to defeat Sweden's enemies and expand the boundaries and the power of the empire long after Gustav Adolf's death in battle.

He is known by the epithets "The Golden King" and "The Lion of the North" by neighboring sovereigns.

Gustavus Adolphus is today commemorated by city squares in Stockholm, Gothenburg and Sundsvall.

Gustavus Adolphus College, a Lutheran college in St. Peter, Minnesota, is also named for the Swedish king.