"The Protestant Reformation, also known as the Protestant Revolt or the Reformation, was the European Christian reform movement that established Protestantism as a constituent branch of contemporary Christianity. It was led by Martin Luther, John Calvin and other early Protestants. The efforts of the self-described "reformers", who objected to ("protested") the doctrines, rituals and ecclesiastical structure of the Catholic Church, led to the creation of new national Protestant churches. The Catholics responded with a Counter-Reformation, led by the Jesuit order, which reclaimed large parts of Europe, such as Poland. In general, northern Europe, with the exception of Ireland and pockets of Britain, turned Protestant, and southern Europe remained Catholic, while fierce battles that turned into warfare took place in the central Europe. The largest of the new denominations were the Anglicans (based in England), the Lutherans (based in Germany and Scandinavia), and the Reformed churches (based in Germany, Switzerland, the Netherlands and Scotland). There were many smaller bodies as well. The most common dating begins in 1517 when Luther published The Ninety-Five Theses, and concludes in 1648 with the Treaty of Westphalia that ended years of European religious wars" Source: Wikipedia