A papal bull issued by Pope Calistus III on 11 July 1458, appointing Thomas as bishop of Sodor and establishing the Church of Sodor as suffragan to the Church of York. The document includes both the English translation and original Latin text, with a memorandum recording its exhibition at London on 18 February 1458. This foundational ecclesiastical document is relevant to understanding the constitutional and religious framework of the Isle of Man before the Revestment.