The Reformation, or Protestant Reformation is generally considered to have begun in 1517, when the theologian-priest, Martin Luther, published The Ninety-Five Theses, which challenged Catholic doctrine on the giving of indulgences, purgatory, "particular judgment," and the authority of the Pope, among other issues. This Protestant Reformation concluded in 1648 with the Peace of Westphalia, and the end of European religious wars. While Luther started by criticizing the above-mentioned issues, debate widened to the point that many of the doctrines and devotional practices of the Catholic Church were questioned.
From the mid-sixteenth century to the mid-seventeenth century, ( approximately the reign of Pope Pius IV to the end of the Thirty Years' War in 1648), the Counter-Reformation took place; this was a movement for reform in the Church in reaction to the challenges of the Protestant Reformation. Literature from this period includes the Spiritual Exercises (c. 1522-23) by St. Ignatius of Loyola, the founder of the Society of Jesus. This order of priests, commonly called Jesuits became the theological scholars of the Church. When the Council of Trent met on December 13, 1545 and closed on December 4, 1563, there was established, according to New Advent, a Catholic encyclopedia,
the definitive determination of the doctrines of the Catholic Church in answer to the heresies of the Protestants; a further object was the execution of a thorough reform of the inner life of the Church by removing the numerous abuses that had developed in it.
According to Huber Jedin, the term "Catholic Reformation" differs from "Counter-Reformation." Whereas the Counter-Reformation was the reaction to the Protestant Reformation, Catholic Reformation emphasizes continuity [Enotes] as reforms have been made in the past and continue in the present. For instance, there was a major split within the Catholic Church from 1378 to 1418. Called the Western Schism, this division in the Church began with the return of the Papacy to Rome under Gregory XI. The move ended the Avignon, France, Papacy which had attained a reputation for corruption. Because the Catholic Church wielded much political power in those times, this relocation sparked more than theological controversy. Other reforms involved the promotion of "active good works" and the doing away with indulgences. More contemporary reforms have been made regarding Church doctrine, especially in the Vatican Council of 1962, the Second Vatican Council ("Vatican II), which modernized many of the practices such as changing the Mass from Latin to English and allowing women at the alter during Mass to assist as readers and giving out Communion.