Protestantism is a form of Christian faith and practice that originates with the Protestant Reformation, a movement against what its followers consider to be errors in the Roman Catholic Church.

It is one of the three major divisions of Christendom, together with Roman Catholicism and Eastern Orthodoxy.

Anglicanism is sometimes considered to be independent from Protestantism.

The term derives from the letter of protestation from Lutheran princes in 1529 against an edict condemning the teachings of Martin Luther as heretical.

With its origins in Germany, the modern movement is popularly considered to have begun in 1517 when Luther publishes The Ninety-Five Theses as a reaction against abuses in the sale of indulgences, which purported to offer remission of sin to their purchasers.

Although there were earlier breaks from or attempts to reform the Roman Catholic Church—notably by Peter Waldo, Arnold of Brescia,Girolamo Savonarola, John Wycliffe, and Jan Hus—only Luther succeeds in sparking a wider, lasting movement.All Protestant denominations reject the notion of papal supremacy over the Church universal and generally deny the Roman Catholic doctrine of transubstantiation, but they disagree among themselves regarding the real presence of Christ in the Eucharist.

The various denominations generally emphasize the priesthood of all believers, the doctrine of justification by faith alone (sola fide) rather than by or with good works, and a belief in the Bible alone (rather than with Catholic tradition) as the highest authority in matters of faith and morals (sola scriptura).

The "Five solae" summarize the reformers' basic differences in theological beliefs in opposition to the teaching of the Roman Catholic Church of the day.

Protestantism spreads on the European continent during the sixteenth century.

Lutheranism spreads from Germany into its surrounding areas, Denmark, Norway, Sweden, Prussia, Latvia, Estonia, and Iceland, as well as other smaller territories.

Reformed churches are founded primarily in Germany and its adjacent regions, Hungary, the Netherlands, Scotland, Switzerland, and France by such reformers as John Calvin, Huldrych Zwingli, and John Knox.

Arminianism gains supporters in the Netherlands and parts of Germany.

In 1534, King Henry VIII puts an end to all papal jurisdiction in England after the Pope fails to annul his marriage to Catherine of Aragon; this opens the door to reformational ideas, notably during the following reign of Edward VI, through Thomas Cranmer, Richard Hooker, Matthew Parker and other theologians.

There are also reformational efforts throughout continental Europe known as the Radical Reformation—a response to perceived corruption in both the Roman Catholic Church and the expanding Magisterial Reformation led by Luther and various other reformers—which give rise to Anabaptist, Moravian, and other Pietistic movements.

In later centuries, Protestants develop their own culture, which makes major contributions in education, the humanities and sciences, the political and social order, the economy and the arts, and other fields.

Collectively encompassing more than nine hundred million adherents, or nearly forty percent of Christians worldwide, Protestantism is present on all populated continents.

The movement is more divided theologically and ecclesiastically than either Eastern Orthodoxy or Roman Catholicism, lacking both structural unity and central human authority.

Some Protestant churches do have a worldwide scope and distribution of membership (notably, the Anglican Communion), while others are confined to a single country, or even are solitary church bodies or congregations (such as the former Prussian Union of churches).

Nondenominational, evangelical, independent and other churches are on the rise, and constitute a significant part of Protestant Christianity.

An exact number of Protestant denominations is difficult to calculate and depends on definition.

Nevertheless, most Protestants are members of just a handful of denominational families: Adventism, Anglicanism, Baptist churches, Reformed churches, Lutheranism, Methodism, and Pentecostalism.