1. How did religion develop unity in Europe ?

The European wars of religion were a series of Christian religious wars which were waged in Europe during the 16th, 17th and early 18th centuries.[1][2] Fought after the Protestant Reformation began in 1517, the wars disrupted the religious and political order in the Catholic countries of Europe. However, religion was only one of the causes, which also included revolts, territorial ambitions, and Great Power conflicts. For example, by the end of the Thirty Years' War (1618–1648), Catholic France was allied with the Protestant forces against the Catholic Habsburg monarchy.[3] The wars were largely ended by the Peace of Westphalia (1648), establishing a new political order 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 in 1545 against the growth of Protestantism. The conflicts culminated in the Thirty Years' War (1618–1648), which devastated Germany and killed one-third of its population, a mortality rate twice that of World War I.[2][4] The Peace of Westphalia (1648) broadly resolved the conflicts by recognising three separate Christian traditions in the Holy Roman Empire: Roman Catholicism, Lutheranism, and Calvinism.[5][6] Although many European leaders were "sickened" by the bloodshed by 1648,[7] smaller religious wars continued to be waged in the post-Westphalian period until the 1710s, including the Wars of the Three Kingdoms (1639–1651) on the British Isles, the Savoyard–Waldensian wars (1655–1690), and the Toggenburg War (1712) in the Western Alps.[2]