Metropolis of Elis and Olena

The Metropolis of Elis and Olena () is a Greek Orthodox episcopal see of the Church of Greece. During the period of Frankish rule it was a Roman Catholic see, and continues to the present day as a titular see in the Roman Catholic Church.
History.
Olena (Ὤλενα, today Oleni) became an episcopal see in Byzantine times, being recorded as the see of Bolaina (Βολαίνα) since the 9th century in the "Notitiae Episcopatuum" of the Patriarchate of Constantinople. It was probably established after the reconquest of the Peloponnese from the Slavs, and was a suffragan of the Metropolis of Patras. 
The see remains attested in the "Notitiae" until the 13th century, but following the Latin conquest of the Peloponnese and the establishment of the Principality of Achaea, it was taken over by a Roman Catholic bishop. On the demand of Prince Geoffrey I of Villehardouin, however, its seat was moved to Andravida, the Principality's capital. The Latin bishops, who remained suffragans of the Latin Archbishop of Patras, resided there until the decline of the Principality, when the region became depopulated; they then moved to Kaminitsa near Patras. 
The Latin see was suppressed when the Principality was conquered by the Despotate of the Morea in 1430, and a Greek Orthodox residential bishop once again took up seat there. 
In Ottoman times, the see was variously based at Gastouni and Pyrgos. Following Greek independence, the vacant see was merged with the Metropolis of Patras, into the Archbishopric of Patras and Elis. In 1899, the Bishopric of Elis became independent, and was promoted to metropolitan see in 1922.
Roman Catholic titular holders.
The see is currently vacant, having had the following non-consecutive incumbents, all of the lowest (episcopal) rank :