Zeki Erenerol, born Pavlos Karahisaridis (Greek: Παύλος Καραχισαρίδης; 1883 – 14 March 1968),[1] papal name Eftim I, was a Turkish Eastern Orthodox cleric of Karamanli origin, who was the first Patriarch of the Autocephalous Turkish Orthodox Patriarchate that he founded.

Karahisaridis was born in Maden kaza (today Akdağmadeni) of Bozok sanjak in 1883, in a Karamanli family hailing from Şebinkarahisar (hence his birth surname).

During the meeting in a convent in Kayseri, the decision was made to establish a Turkish Christian church independent of the Ecumenical Patriarch of Constantinople.

On 6 June 1924, in a conference in the Church of the Virgin Mary (Meryem Ana) in Galata, it was decided to transfer the headquarters of the Turkish Orthodox Patriarchate from Kayseri to Istanbul.

[8] Most of the Turkish speaking Orthodox population remained affiliated with the Greek Ecumenical Patriarchate of Constantinople.

He resigned in 1962 due to ill health and his elder son Turgut Erenerol (formerly Giorgios Karahisaridis) became Papa Eftim II, and held this post until his death in 1991.

The office was then passed to his younger son Selçuk Erenerol, who took the title Papa Eftim III until 2002.