John Campanus was one of the two most notorious Antitrinitarians of northern Europe in the second quarter of the sixteenth century. While, unlike the other, Michael Servetus, he does not seem to have had any lasting marked influence on Antitrinitarian developments, the stir he created among his comtemporaries was considerable. His stature in his own time is partially attested to, albeit negatively, both in a letter of Luther's in 1531 in which he identified Campanus as an adversary of the Son of God who blasphemed Christ even more than Arius had,2 and in the “mild” Melanchthon's opinion— given in response to a statement by Luther that the best way to deal with Campanus was to ignore him—that one should, rather, hitch him to the gallows. Somewhat more positive esteem, on the other hand, is intimated in a letter written to Cardinal Cervini in 1541 by the Catholic reformer Albert Pighius, whose opinion it was of one of Campanus' writings that no other writing of the time, either by a Catholic or a Lutheran, displayed greater erudition and ingenuity.