Battle of Breitenfeld (1631) in the context of "Johann Tserclaes, Count of Tilly"

Gustavus Adolphus (9 December [N.S 19 December] 1594 – 6 November [N.S 16 November] 1632), also known in English as Gustav II Adolf or Gustav II Adolph, was King of Sweden from 1611 to 1632. He is credited with the rise of Sweden as a great European power (Swedish: Stormaktstiden). During his reign, Sweden became one of the primary military forces in Europe during the Thirty Years' War, helping to determine the political and 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.

He is often regarded as one of the greatest military commanders in modern history, with use of an early form of combined arms. His most notable military victory was the Battle of Breitenfeld in 1631. With his resources, logistics, and support, Gustavus Adolphus was positioned to become a major European leader, but he was killed a year later at the Battle of Lützen. He was assisted in his efforts by Count Axel Oxenstierna, the Lord High Chancellor of Sweden, who also acted as regent after his death.

The line formation is a standard tactical formation which was used in early modern warfare.It continued the phalanx formation or shield wall of infantry armed with polearms in use during antiquity and the Middle Ages.

The line formation provided the best frontage for volley fire, while sacrificing maneuverability and defence against cavalry. It came to the fore during the Age of Reason, when it was used to great effect by Frederick the Great and his enemies during the Seven Years' War. The line formation was very successfully first used with combined arms in the Thirty Years War by the Swedish king Gustavus Adolphus the Great, at the Battle of Breitenfeld.