The reform is the religious revolution which divided the Christians into catholics and Protestants.
It occurs initially in Germany, where it is supported by the parcelling out of the Empire in a great number of small almost independent States.
The Luther monk, after having only tackled the abuse indulgences (1517), breaks openly with the Pope (1520), condemns the celibacy of the priests and the monastic vows rejects a part of the catholic dogmas, denies the infallibility of the Councils like that of the Pope, and proclaims the Scriptures the only base of the faith.
Put at the round of applause of the Empire by Charles-Quint, it finds in the duke of Saxony Frederic Wise powerful guard; its doctrines are spread in Germany of North; written by Mélanchton under the name of Confession of Augsburg (1530), developed by Calvin in his book ofthe Christian Institution (1535), they are propagated quickly.
In vain the Reform is condemned by the council of Thirty (1545); threatened in their life or their freedom, Réformés takes the weapons after the death of Luther (1546); overcome by Charles-Quint with Mühlberg in 1547, they are saved by France and obtain honourable conditions by the peace of Augsburg (1555).
Calvin, who replaced Luther as chief of the reformed party, moves away even more than him of Catholicism and organizes his religion in Geneva.
In France the reform of Luther does few proselytes, but that of Calvin is spread there, especially in the South, in spite of the Sorbonne, the Parliaments and the king; at the end of the reign of Henri II, it counts already two thousand churches.