Johann Tserclaes, Count of Tilly was a field marshal who commanded the Catholic League's forces in the Thirty Years' War. From 1620–31, he had an unmatched and demoralizing string of important victories against the Protestants, including White Mountain, Wimpfen, Höchst, Stadtlohn and the Conquest of the Palatinate. He destroyed a Danish army at Lutter and sacked the Protestant city of Magdeburg, which caused the death of some 20,000 of the city's inhabitants, both defenders and non-combatants, out of a total population of 25,000.

The Thirty Years' War was one of the longest and most destructive conflicts in European history, lasting from 1618 to 1648. Fought primarily in Central Europe, an estimated 4.5 to 8 million soldiers and civilians died as a result of battle, famine, or disease, while parts of present-day Germany reported population declines of over 50%. Related conflicts include the Eighty Years' War, the War of the Mantuan Succession, the Franco-Spanish War, the Torstenson War, the Dutch-Portuguese War, and the Portuguese Restoration War.