rebaptism for Roman Catholics converting to Orthodox Christianity Council of Constantinople (1848), issued the Encyclical of the Eastern Patriarchs, a reply to Pope Pius IX's In Suprema Petri Apostoli Sede epistle (also titled the Epistle to the Easterners) Council of Constantinople (1872), condemned phyletism as a non-Orthodox schismatic movement Council of Constantinople (1923), a major council, (although not ecumenical,) introduced several reforms, most controversially the revised Julian calendar reform