The Protestant Reformation was a 16th-century split within Western Christianity initiated 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 Roman Catholic Church, led to the creation of new national Protestant churches. The Reformation was precipitated by earlier events within Europe, such as the Black Death and the Western Schism, which eroded people's faith in the Roman Catholic Church. This, as well as many other factors, contributed to the growth of lay criticism in the church and the creation of Protestantism.
The Roman Catholics responded with a Counter-Reformation, led by the Jesuit order, which established influence over large parts of Europe such as Poland. In general, northern Europe, with the exception of Ireland and pockets of Britain, turned Protestant. Southern Europe remained Roman Catholic, while fierce battles which turned into warfare took place in central Europe.
The largest of the new churches were the Lutherans (mostly in Germany and Scandinavia) and the Reformed churches (mostly 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.
