First Battle of Breitenfeld

Breitenfeld was the first major Protestant victory of the Thirty Years' War, ending a long run of Catholic triumphs and rescuing the Protestant cause in Germany. Gustavus Adolphus's smaller, mobile lines of musketeers firing in coordinated salvoes, backed by fast, light field guns, tore apart Tilly's massive slow squares of pike and shot. Early in the day the raw Saxon wing collapsed and fled and nearly lost the battle, but the Swedes redeployed to cover the gap. They then wheeled, captured the Imperial artillery, and turned the enemy's own guns on the tercios. The victory announced Sweden as a first-rank European power and made its king the dominant figure of the war.

Breitenfeld is taught as the debut of modern linear and combined-arms tactics, the flexible shallow formations, salvo fire, mobile artillery and integrated cavalry that broke the century-old dominance of the deep Spanish-style tercio. It is also remembered as the moment Sweden vaulted from a peripheral Baltic kingdom to a European great power. Historians debate how revolutionary the Swedish system truly was, against how much it owed to earlier Dutch reforms and to Tilly's own mistakes on the day. The argument is really about whether battles make revolutions or merely reveal them.