The Archdiocese of Venice was elevated to an honorary Patriarchate by the pope on 8 October 1457 when the Patriarchate of Grado was suppressed .
The Patriarchate of Grado is a successor to the Patriarchate of Aquileia .
The Archdiocese of Venice was elevated to an honorary Patriarchate by the pope on 8 October 1457 when the Patriarchate of Grado , a successor to the Patriarchate of Aquileia , was suppressed .