Theodosiopolis was important enough in the Late Roman province of Armenia Tertia to become a bishopric, which the Annuario Pontificio lists as suffragan of the Archdiocese of Comachus, but in Notitiae Episcopatuum from the seventh and early tenth centuries, its (later?)
Metropolitan is the Archdiocese of Caesarea in Cappadocia.
In either case, it was in the sway of the Patriarchate of Constantinople.

Its historically recorded Suffragan Bishops were :
Petrus I, intervening at the council of 448 convoked by Patriarch Flavian of Constantinople in his see to condemn Archimandrite Eutyches as a heretic for his extreme opposition to Nestorianism
Manasse intervened at the Council of Chalcedon in 451
Petrus II participated in the 533 dispute in Constantinople between 'orthodoxy' and Monophysitism
As ancient Theodosiopolis in Armenia (or "in Cappadocia"), the former bishopric remains a Latin Catholic titular see.
Theodosiopolis was important enough in the Late Roman province of Armenia Tertia to become a bishopric, which the Annuario Pontificio lists as suffragan of the Archdiocese of Comachus, but in Notitiae Episcopatuum from the seventh and early tenth centuries, its (later?) Metropolitan is the Archdiocese of Caesarea in Cappadocia. In either case, it was in the sway of the Patriarchate of Constantinople.
Its historically recorded Suffragan Bishops were :
Petrus I, intervening at the council of 448 convoked by Patriarch Flavian of Constantinople in his see to condemn Archimandrite Eutyches as a heretic for his extreme opposition to Nestorianism
Manasse intervened at the Council of Chalcedon in 451
Petrus II participated in the 533 dispute in Constantinople between 'orthodoxy' and Monophysitism
As ancient Theodosiopolis in Armenia (or "in Cappadocia"), the former bishopric remains a Latin Catholic titular see.
Erzurum