Although there had been some attempts at reforming the Church in the late fourteenth century, most notably by John Wycliffe and Jan Hus, it is Martin Luther, John Calvin, and other early Protestants who initiated the schism within Western Christianity, which became known as the Reformation. This is usually dated back to 1517, the year when Luther published his ‘Ninety Five Theses’, ending in 1648 with the peace of Westphalia which ended the European wars of religion.
The starting criticism for Luther was the relatively recent practice of indulgences, whereby time in purgatory could be reduced against payment to the Church. However, the debate eventually touched on many of the doctrines and devotional practices of the Roman Catholic Church.
The reformation led to the creation of national Protestant churches such as the Lutherans in Germany, the Baltics and Scandinavia, and the Reformed churches in Germany, France, Switzerland, the Netherlands and Scotland.
It also influenced the direction of the Church of England after 1547 under Edward VI and Elizabeth I, although it had already become independent for political reasons in the early 1530s under Henry VIII.
While the main motivation for the reformation was theological, many other factors played a part, including the corruption of the Papacy and the Curia, the Renaissance which questioned much traditional thought, and the rise of nationalism. The invention of the printing press proved extremely significant in that it provided the means for the rapid dissemination of new ideas, as well as the printing of translations of the Bible.
The Council of Trent of the Roman Catholic Church met from 1545-1563 and most notably created the new order of the Society of Jesus (Jesuits) to counter the Protestant movement.
The geographical religious landscape changed significantly, with Northern Europe, with the exception of most of Ireland, turning Protestant, Southern Europe remaining Roman Catholic, and Central Europe becoming a site of fierce conflict, escalating to full-scale religious war.