It is the Catholic counterpart of the Greek Orthodox Metropolis of Ephesus, which is a titular bishopric under Patriarchate of Constantinople (in Greek: Μητρόπολις Εφέσου; Mitrópolis Efesou).
Both the Catholic and Orthodox churches lay claim to the ancient bishopric founded in the 1st century by Saint Timothy.
[4] Beginning in the 14th century,[5][6] Ephesus was one of the archbishopric claimed by the Catholic Church, due in part to the Catholic Church involvement in the east Mediterranean.
The first known bishop was Franciscan named Corrado (fl1318) whom Le Quien called vir doctus et in linguis orientalis versatus.
The last Catholic holder was Giovanni Enrico Boccella,[8][9] emeritus bishop of Smyrna, who died on 22 May 1992.