At an earlier stage, Trapezopolis was part of Caria, as reported by Ptolemy and Pliny the Elder, but by the time of Socrates of Constantinople, Hierocles and the various Notitiae Episcopatuum it belonged to Phrygia Pacatiana.
The bishopric of Trapezopolis was a suffragan of Laodicea, the capital and metropolitan seat of the province of Phrygia Pacatiana Prima. It is mentioned as a residential see until the 13th century and is now included in the Catholic Church's list of titular seats.
- Hierophilius, prior to 400;
- Asclepiades, present at the Council of Ephesus (431);
- John, at the Council of Chalcedon (451);
- Eugenius, at the Trullan Council (692);
- Zacharias, at Second Council of Nicaea (787);
- Leo, at the Fourth Council of Constantinople (Roman Catholic) (879).
- Ptolemy. The Geography. Vol. 2.2.18.
- Sophrone Pétridès, "Trapezopolis" in Catholic Encyclopedia (New York 1912)
- Richard Talbert, ed. (2000). Barrington Atlas of the Greek and Roman World. Princeton University Press. p. 65, and directory notes accompanying.
- Lund University. Digital Atlas of the Roman Empire.
- Annuario Pontificio 2013 (Libreria Editrice Vaticana, 2013, ISBN 978-88-209-9070-1), p. 995
- Le Quien, Michel (1740). Oriens Christianus, in quatuor Patriarchatus digestus: quo exhibentur ecclesiæ, patriarchæ, cæterique præsules totius Orientis. Tomus primus: tres magnas complectens diœceses Ponti, Asiæ & Thraciæ, Patriarchatui Constantinopolitano subjectas (in Latin). Paris: Ex Typographia Regia. cols. 809-810. OCLC 955922585.