Maurice of Nassau in the context of "Guelders"

Line infantry was the type of infantry that formed the bulk of most European land armies from the mid-17th century to the mid-19th century. Maurice of Nassau and Gustavus Adolphus are generally regarded as its pioneers, while Turenne and Montecuccoli are closely associated with the post-1648 development of linear infantry tactics. For both battle and parade drill, it consisted of two to four ranks of foot soldiers drawn up side by side in rigid alignment, and thereby maximizing the effect of their firepower. By extension, the term came to be applied to the regular regiments "of the line" as opposed to light infantry, skirmishers, militia, support personnel, plus some other special categories of infantry not focused on heavy front line combat.

Henri de La Tour d'Auvergne, vicomte de Turenne (11 September 1611 – 27 July 1675), commonly known as Turenne (French: [tyʁɛn]), was a French general and one of only six marshals to have been promoted Marshal General of France. The most illustrious member of the La Tour d'Auvergne family, his military exploits over his five-decade career earned him a reputation as one of the greatest military commanders in history.

Born to a Huguenot family, the son of a Marshal of France, he was introduced to the art of war at a young age. He first served as a volunteer in the Dutch States Army under the orders of his maternal uncles Maurice of Nassau and Frederick Henry before pursuing his career in the service of France, where his noble origins and proven qualities soon saw him rise to the top of the military hierarchy. He rose to prominence during the Thirty Years' War by capturing the fortress of Breisach in 1638. Promoted Marshal of France in 1643, he struck against Bavaria the following year, defeating the Bavarian army in three years of campaigning and forcing the Elector of Bavaria to make peace. The Elector soon broke the treaty and in 1648 Turenne invaded again with Swedish support, subduing the Imperial army at Zusmarshausen and pacifying Bavaria.