December 23, 1572
Heidelberg, Germany
Reformed German theologian Johann Sylvan is executed for publishing antitrinitarian literature

Sylvan had published a thesis entitled “True Christian Confession of the Ancient Faith of the One True God and of Messiah Jesus of the True Christ, against the Three-Person Idol and the Two-Natured False Deity of the Antichrist,” an antitrinitarian piece which called attention to the lack of evidence in Christian and Jewish scriptures supporting the concept of a Holy Trinity or that the divine is constructed of 3 parts. For his heresy Sylvan was beheaded in the Heidelberg marketplace. He is now considered a martyr by unitarians.