Caesarea was an important diocese, and its bishop was, ex officio, exarch of the great diocese of Pontus.
Finally, in the pinnae of the frond the centrifugal xylem may disappear, the protoxylem being now exarch in position and abutting on the phloem.
In 568 the Lombards found Mantua a walled town of some strength; recovered from their grasp in 590 by the exarch of Ravenna, it was again captured by Agilulf in 601.
On the 18th of March 339 the exarch of Egypt suddenly confronted Athanasius with an imperial edict, by which he was deposed and a Cappadocian named Gregory was nominated bishop in his place.
The title of Exarch was also formerly given in the Eastern Church to a general or superior over several monasteries, and to certain ecclesiastics deputed by the patriarch of Constantinople to collect the tribute payable by the Church to the Turkish government.
In 606 the diocese was divided into two parts, and the patriarchate of Aquileia, protected by the Lombards, was revived, that of Grado being protected by the exarch of Ravenna and later by the doges of Venice.
This body now governs the Russian Church, and consists of a procurator representing the emperor, the metropolitans of Kiev, Moscow and St Petersburg, the exarch of Georgia and five or six other bishops appointed by the emperor.
One of them was the Greek exarch of Tangier, Julian, who, supported by the powerful Berber tribe of Ghomera, had long resisted and even asked for aid from Spain, but had been compelled to surrender and was left governor of Ceuta.
At the time of the Arab invasion it was the capital of the exarch Gregorius, and outside its walls the battle was fought in which he was slain; his daughter, who is said by the Arab historians to have fought by the side of her father, became the wife of one of the Arab leaders.
The title of exarch has been borne by the head of the Bulgarian Church (see BULGARIA), since in 1872 it repudiated the jurisdiction of the Greek patriarch of Constantinople.