Line infantry
Line infantry was the type of infantry that composed the basis of European land armies from the late 17th century to the middle of the 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.