The European wars of religion were a series of wars waged in Europe during the 16th, 17th and early 18th centuries. Fought after the Protestant Reformation began in 1517, the wars disrupted the religious and political order in the Catholic countries of Europe, or Christendom. Other motives during the wars involved revolt, territorial ambitions and great power conflicts. By the end of the Thirty Years' War (1618–1648), Catholic France had allied with the Protestant forces against the Catholic Habsburg monarchy. The wars were largely ended by the Peace of Westphalia (1648), which established a new political order that is now known as Westphalian sovereignty.
The conflicts began with the minor Knights' Revolt (1522), followed by the larger German Peasants' War (1524–1525) in the Holy Roman Empire. Warfare intensified after the Catholic Church began the Counter-Reformation against the growth of Protestantism in 1545. The conflicts culminated in the Thirty Years' War, which devastated Germany and killed one third of its population, a mortality rate twice that of World War I. The Peace of Westphalia broadly resolved the conflicts by recognising three separate Christian traditions in the Holy Roman Empire: Roman Catholicism, Lutheranism, and Calvinism. Smaller religious wars continued to be waged in Western Europe until the 1710s, including the Wars of the Three Kingdoms (1639–1651) in the British Isles, the Savoyard–Waldensian wars (1655–1690), and the Toggenburg War (1712) in the Western Alps.
The European wars of religion are also known as the Wars of the Reformation. In 1517, Martin Luther's Ninety-five Theses took only two months to spread throughout Europe with the help of the printing press, overwhelming the abilities of Holy Roman Emperor Charles V and the papacy to contain it. In 1521, Luther was excommunicated, sealing the schism within Western Christendom between the Roman Catholic Church and the Lutherans and opening the door for other Protestants to resist the power of the papacy.