The Treatise on the Power and Primacy of the Pope (1537) (Latin, Tractatus de Potestate et Primatu Papae), The Tractate for short, is the seventh Lutheran credal document of the Book of Concord. Philip Melanchthon, its author, completed it on February 17, 1537 during the assembly of princes and theologians in Smalcald. (Introduction by Wikipedia)