Protestantism is popularly considered to have begun in Germany[c] 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[d] into Denmark, Norway, Sweden, Finland, Latvia, Estonia, and Iceland. Reformed (or Calvinist) denominations spread in Germany,[e] 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.[f]
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[g] are members of a handful of Protestant denominational families: Adventists, Anabaptists, Anglicans, Baptists, Reformed,[h] 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).
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 (1529), 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, though initially purely political in nature, 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.
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.
The word evangelical (German: evangelisch), which refers to the gospel, was widely used for those involved in the religious movement in the German-speaking area beginning in 1517. Nowadays, evangelical is still preferred among some of the historical Protestant denominations in the Lutheran, Calvinist, and United Protestant (Lutheran & Reformed) traditions in Europe, and those with strong ties to them (e.g. Wisconsin Evangelical Lutheran Synod). Above all the term is used by Protestant bodies in the German-speaking area, such as the Evangelical Church in Germany. In continental Europe, an Evangelical is either a Lutheran, a Calvinist, or a United Protestant (Lutheran & Reformed). The German word evangelisch means Protestant, and is different from the German evangelikal, which refers to churches shaped by Evangelicalism. The English word evangelical usually refers to evangelical Protestant churches, and therefore to a certain part of Protestantism rather than to Protestantism as a whole. The English word traces its roots back to the Puritans in England, where Evangelicalism originated, and then was brought to the United States.
Martin Luther always disliked the term Lutheran, preferring the term evangelical, which was derived from euangelion, a Greek word meaning "good news", i.e. "gospel". The followers of John Calvin, Huldrych Zwingli, and other theologians linked to the Reformed tradition also began to use that term. To distinguish the two evangelical groups, others began to refer to the two groups as Evangelical Lutheran and Evangelical Reformed. Nowadays, the word also pertains in the same way to some other mainline groups, for example Evangelical Methodist. As time passed by, the word evangelical was dropped. Lutherans themselves began to use the term Lutheran in the middle of the 16th century, in order to distinguish themselves from other groups such as the Philippists and Calvinists.