Line Infantry Tactics

Timeline

1. c. 1620–1650Battlefields of the Holy Roman Empire · Holy Roman EmpireSwedish king Gustavus Adolphus broke up the traditional Spanish tercio during the Thirty Years' War, creating a shallow line only six ranks deep, alternating musketeers and pikemen and adopting volley fire, greatly increasing sustained infantry firepower density; he is regarded as the direct precursor of line infantry tactics.
2. 1650–1672France and the Low Countries · Western EuropeAfter Louis XIV assumed personal rule, the Marquis de Louvois led French army reforms, simplifying infantry units from mixed-weapon formations into homogeneous lines of mainly flintlock-armed men drawn up three to four ranks deep; concurrently William III of Orange standardized Dutch army training, and the two sides learned from each other in war, establishing a common training foundation for European line infantry.
3. 1672–1678Battlefields of France, Holland, and the Spanish Netherlands · Western EuropeThe Franco-Dutch War (1672-1678) was the first large-scale test of line infantry tactics. French three-rank continuous volleys clashed repeatedly with Dutch defensive formations in field and siege warfare, proving the feasibility of flintlock plus socket bayonet replacing the pike. After the war European military theorists systematically summarized line tactics, greatly raising their degree of standardization.
4. 1678–1700European national armies · EuropeThe socket bayonet (widely adopted in the French army around 1678) completely eliminated the rationale for pikemen; infantry were unified as flintlock-armed bayonet men drawn up two to three ranks deep, firing alternating volleys. By around 1700 Britain, Holland, Prussia, Austria and others had institutionalized the system, and line infantry tactics became the dominant form on 18th-century European battlefields until the rise of column-and-skirmisher tactics in the Napoleonic era.