Protestantism is popularly considered to have begun in Germany in 1517 when Martin Luther published his Ninety-five Theses as a reaction against abuses in the sale of indulgences by the Roman Catholic Church, which purported to offer remission of sin to their purchasers. However, the term derives from the letter of protestation from German Lutheran princes in 1529 against an edict of the Diet of Speyer condemning the teachings of Martin Luther as heretical. Although there were earlier breaks and attempts to reform the Roman Catholic Church — notably by Peter Waldo, John Wycliffe, and Jan Hus — only Luther succeeded in sparking a wider, lasting, and modern movement. In the 16th century, Lutheranism spread from Germany into Denmark, Norway, Sweden, Finland, Latvia, Estonia, and Iceland. Reformed (or Calvinist) denominations spread in Germany, Hungary, the Netherlands, Scotland, Switzerland and France by reformers such as John Calvin, Huldrych Zwingli, and John Knox. The political separation of the Church of England from the pope under King Henry VIII began Anglicanism, bringing England and Wales into this broad Reformation movement.
Protestants developed their own culture, with major contributions in education, the humanities and sciences, the political and social order, the economy and the arts, and many other fields.
Protestantism is diverse, being more divided theologically and ecclesiastically than either the Roman Catholic Church, the Eastern Orthodox Church, or Oriental Orthodoxy. Without structural unity or central human authority, Protestants developed the concept of an invisible church, in contrast to the Roman Catholic view of the Catholic Church as the visible one true Church founded by Jesus Christ. Some denominations do have a worldwide scope and distribution of membership, while others are confined to a single country. A majority of Protestants are members of a handful of Protestant denominational families: Adventists, Anabaptists, Anglicans, Baptists, Reformed, Lutherans, Methodists, and Pentecostals. Nondenominational, evangelical, charismatic, independent and other churches are on the rise, and constitute a significant part of Protestant Christianity. Proponents of the branch theory consider Protestantism one of the three major divisions of Christendom, together with the Roman Catholic Church and Orthodoxy (both Eastern and Oriental).
During the Reformation, the term protestant was hardly used outside of German politics. People who were involved in the religious movement used the word evangelical (German: evangelisch). For further details, see the section below. Gradually, protestant became a general term, meaning any adherent of the Reformation in the German-speaking area. It was ultimately somewhat taken up by Lutherans, even though Martin Luther himself insisted on Christian or evangelical as the only acceptable names for individuals who professed Christ. French and Swiss Protestants instead preferred the word reformed (French: réformé), which became a popular, neutral, and alternative name for Calvinists.
Six princes of the Holy Roman Empire and rulers of fourteen Imperial Free Cities, who issued a protest (or dissent) against the edict of the Diet of Speyer, were the first individuals to be called Protestants. The edict reversed concessions made to the Lutherans with the approval of Holy Roman Emperor Charles V three years earlier. The term protestant later acquired a broader sense, referring to a member of any Western church which subscribed to the main Protestant principles. However, it is often misused to mean any church outside the Roman and Eastern Orthodox communions. Protestantism as a general term is now used in contradistinction to the other major Christian traditions, i.e. Roman Catholicism and Orthodoxy.