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 burgomaster Besançon Hugues, who ironically defended Geneva from Catholic Savoy but then let it fall to Protestantism, was in common use by around 1550. 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.