The Huguenots are a religious group of French Protestants who held to the Reformed (Calvinist) tradition of Protestantism. The term, which may be derived from the name of a Swiss political leader, the Genevan burgomaster Besançon Hugues, was in common use by the mid-16th century. Huguenot was frequently used in reference to those of the Reformed Church of France from the time of the Protestant Reformation. By contrast, the Protestant populations of eastern France, in Alsace, Moselle, and Montbéliard, were mainly Lutherans.
In his Encyclopedia of Protestantism, Hans Hillerbrand wrote that on the eve of the St. Bartholomew's Day massacre in 1572, the Huguenot community made up as much as 10% of the French population.