The Protestant Reformation was a reform movement in Europe that began in 1517, though its roots lie further back in time. It began with Martin Luther and may be considered to have ended with the Peace of Westphalia in 1648. The movement began as an attempt to reform the Catholic Church. Many western Catholics were troubled by what they saw as false doctrines and malpractices within the Church, particularly involving the teaching and sale of indulgences. Another major contention was the practice of buying and selling church positions (simony) and what was seen at the time as considerable corruption within the Church's hierarchy. This corruption was seen by many at the time as systemic, even reaching the position of the Pope.

Martin Luther's spiritual predecessors included men such as John Wycliffe and Jan Hus, who had attempted to reform the church along similar lines, though their efforts had been largely unsuccessful. The Reformation can be said to have begun in earnest on October 31, 1517, in Wittenberg, Saxony (in present-day Germany). There, Luther nailed his Ninety-Five Theses to the door of the All Saints' Church, which served as a notice board for university-related announcements. These were points for debate that criticized the Church and the Pope. The most controversial points centered on the practice of selling indulgences and the Church's policy on purgatory. Other reformers, such as Ulrich Zwingli, soon followed Luther's lead. Church beliefs and practices under attack by Protestant reformers included purgatory, particular judgment, devotion to Mary (Mariology), the intercession of and devotion to the saints, most of the sacraments, the mandatory celibacy requirement of its clergy (including monasticism), and the authority of the Pope.

The reform movement soon split along certain doctrinal lines. Spiritual disagreements between Luther and Zwingli, and later between Luther and John Calvin, led to the emergence of rival Protestant churches. The most important denominations to emerge directly from the Reformation were the Lutherans, and the Reformed/Calvinists/Presbyterians. The process of reform had decidedly different causes and effects in other countries. In England, where it gave rise to Anglicanism, the period became known as the English Reformation. Subsequent Protestant denominations generally trace their roots back to the initial reforming movements. The reformers also accelerated the Catholic or Counter Reformation within the Catholic Church. The Protestant Reformation is also referred to as the German Reformation, Protestant Revolution, Protestant Revolt, and, in Germany, as the Lutheran Reformation.

Martin Luther (November 10, 1483 February 18, 1546) was a German monk,Plass, Ewald M. "Monasticism," in What Luther Says: An Anthology. St. Louis: Concordia Publishing House, 1959, 2:964. theologian, university professor, Father of Protestantism,Challenges to Authority: The Renaissance in Europe: A Cultural Enquiry, Volume 3, by Peter Elmer, page 25"Martin Luther: Biography." AllSands.com. July 26, 2008 http://www.allsands.com/potluck3/martinlutherbi_ugr_gn.htm>."What ELCA Lutherns Believe." Evangelical Lutheran Church in America. July 26, 2008 .Saraswati, Prakashanand. The True History and the Religion of India : A Concise Encyclopedia of Authentic Hinduism. New York: Motilal Banarsidass (Pvt. Ltd), 2001. "His 'protest for reformation' coined the term Protestant, so he was called the father of Protestantism." and church reformer whose ideas influenced the Protestant Reformation and changed the course of Western civilization.Hillerbrand, Hans J. "Martin Luther: Significance," Encyclopaedia Britannica, 2007.

Luther's theology challenged the authority of the papacy by holding that the Bible is the only infallible source of religious authorityEwald M. Plass, What Luther Says, 3 vols., (St. Louis: CPH, 1959), 88, no. 269; M. Reu, Luther and the Scriptures, Columbus, Ohio: Wartburg Press, 1944), 23. and that all baptized Christians under Jesus are a universal priesthood.Luther, Martin. Concerning the Ministry (1523), tr. Conrad Bergendoff, in Bergendoff, Conrad (ed.) Luther's Works. Philadelphia: Fortress Press, 1958, 40:18 ff. According to Luther, salvation is a free gift of God, received only by true repentance and faith in Jesus as the Messiah, a faith given by God and unmediated by the church.

At the Diet of Worms assembly over freedom of conscience in 1521, Luther's confrontation with the Holy Roman Emperor Charles V and his refusal to submit to the authority of the Emperor resulted in his being excommunicated from the Roman Catholic Church and being declared an outlaw of the state as a consequence.

His translation of the Bible into the vernacular of the people made the Scriptures more accessible to them, and had a tremendous political impact on the church and on German culture. It furthered the development of a standard version of the German language, added several principles to the art of translation,Fahlbusch, Erwin and Bromiley, Geoffrey William. The Encyclopedia of Christianity. Grand Rapids, MI: Leiden, Netherlands: Wm. B. Eerdmans; Brill, 1999?2003, 1:244. and influenced the translation of the English King James Bible.Tyndales New Testament, trans. from the Greek by William Tyndale in 1534 in a modern-spelling edition and with an introduction by David Daniell. New Haven, CT: Yale University Press, 1989, ix?x. His hymns inspired the development of congregational singing within Christianity.Bainton, Roland. Here I Stand: a Life of Martin Luther. New York: Penguin, 1995, 269. His marriage to Katharina von Bora set a model for the practice of clerical marriage within Protestantism.Bainton, Roland. Here I Stand: a Life of Martin Luther. New York: Penguin, 1995, 223.

Much scholarly debate has concentrated on Luther's writings about the Jews. His statements that Jews' homes should be destroyed, their synagogues burned, money confiscated and liberty curtailed were revived and used in propaganda by the Nazis in 1933?45.McKim, Donald K. (ed.) The Cambridge Companion to Martin Luther. New York: Cambridge University Press, 2003, 58; Berenbaum, Michael. "Anti-Semitism," Encyclopaedia Britannica, accessed January 2, 2007. For Luther's own words, see Luther, Martin. "On the Jews and Their Lies," tr. Martin H. Bertram, in Sherman, Franklin. (ed.) Luthers Works. Philadelphia: Fortress Press, 1971, 47:268?72. As a result of this and his revolutionary theological views, his legacy remains controversial.Hendrix, Scott H. "The Controversial Luther", Word & World 3/4 (1983), Luther Seminary, St. Paul, MN, p. 393: "And, finally, after the Holocaust and the use of his anti-Jewish statements by National Socialists, Luthers anti-semitic outbursts are now unmentionable, though they were already repulsive in the sixteenth century. As a result, Luther has become as controversial in the twentieth century as he was in the sixteenth." Also see Hillerbrand, Hans. "The legacy of Martin Luther", in Hillerbrand, Hans & McKim, Donald K. (eds.) The Cambridge Companion to Luther. Cambridge University Press, 2003.