Its archdeaconries include the cities of Kozani, Aiani, Drepano, Krokos, Servia and Velvendos.
As of 2012[update] the Bishop of the Holy Diocese of Servia and Kozani was Pavlos Papalexiou.
It was first mentioned in the fifth century as the Bishopric of Caesarea[1] under the jurisdiction of the Diocese of Larissa.
[2] An Ancient Greek marble tombstone was found having the inscription: "...προεδρίαν έλαχεν τη Εκκλησία Καισάρων πόλεως Μακεδόνιος έστιν ούτος ανήρ τα παντ’ εύφημος ος Επισκοπήσας έτη εν μήνα ένα του τήδε βίου εκδημήσας μηνί Ιανουαρίω ΚΓ′ Ινδικτιώνος ΙΑ′ προς Θεόν ενεδήμησεν...".
In 1923, when Greek refugees from Asia Minor fled to Kozani, the House of the Diocese was used as a hospital and temporary shelter.