John of Gothia was Greek Orthodox

Eastern Orthodox Church

The Orthodox Church, officially called the Orthodox Catholic Church and commonly referred to as the Eastern Orthodox Church, is the second largest Christian denomination in the world, with an estimated 300 million adherents mainly in the countries of Belarus, Bulgaria, Cyprus, Georgia, Greece,...

 Bishop

Bishop

A bishop is an ordained or consecrated member of the Christian clergy who is generally entrusted with a position of authority and oversight. Within the Catholic Church, Eastern Orthodox, Oriental Orthodox Churches, in the Assyrian Church of the East, in the Independent Catholic Churches, and in the...

 of Gothia

Gothia

Gothia is a name given to various places where the Goths lived during their migrations:* Götaland, the traditional original homeland of the Goths.* Dacia was referred to as Gothia during the fourth century, when it was settled by Goths....

 and Metropolitan

Metropolitan bishop

In Christian churches with episcopal polity, the rank of metropolitan bishop, or simply metropolitan, pertains to the diocesan bishop or archbishop of a metropolis; that is, the chief city of a historical Roman province, ecclesiastical province, or regional capital.Before the establishment of...

 of Doros

Mangup

Mangup also known as Mangup Kale is a historic fortress in Crimea, located on a plateau about 9 miles due east of Sevastopol . In medieval times it was known as Doros, later it was given the Kipchak name Mangup .- History :The settlement dates back to the 3rd century CE and was fortified by...

, a stronghold of the Crimean Goths

Crimean Goths

Crimean Goths were those Gothic tribes who remained in the lands around the Black Sea, especially in Crimea. They were the least-powerful, least-known, and almost paradoxically, the longest-lasting of the Gothic communities...

, in the mid to late 700s CE.

In 787 John led a revolt against Khazar domination of Gothia. The Khazar garrison and tudun

Tudun

A tudun was a governor resident in a town or other settlement in Ancient Bulgar/Avar/Gokturk empires, particularly those of the Bulgars and the Khazars. In Gothic THIUDNASSAM means 'kingdom'. The tudun was the personal representative of the imperial government and could function both as an...

 were expelled from Doros, but returned and retook the city in less than a year. John was imprisoned in Itil

Atil

Atil , literally meaning "Big River", was the capital of Khazaria from the middle of the 8th century until the end of the 10th century. The word is also a Turkic name for the Volga River.-History:...

for a time before being released.