It was first mentioned in the fifth century as the
Bishopric of Caesarea under the jurisdiction of the Diocese of
Larissa. 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...". Archaeologists infer that the tombstone was written in the 5th century and that the Bishopric of Caesarea was established in the 4th century, when persecution against Christians ceased. The Bishopric of Caesarea was moved to Servia from the 9th century onwards. It is
Leo VI the Wise who first mentions the new "Bishopric of Servia", which kept its name until 1745. The seat was then moved to
Kozani and the title was changed to
Bishopric of Servia and Kozani being under the jurisdiction of the
Metropolitan see of
Thessalonica. In 1882 the bishopric was promoted to a Metropolis and from then has been under the jurisdiction of the
Ecumenical Patriarchate. In 1923, when
Greek refugees from
Asia Minor fled to
Kozani, the House of the Diocese was used as a hospital and temporary shelter. During the
German occupation of Greece (1941–44) the House of the Diocese was occupied by German troops and much of its historical archive was destroyed or lost. ==Monasteries==