Diocese of Armenia was anEast Syriac diocese (and briefly ametropolitan province) of theChurch of the East between the fifth and fourteenth centuries. The diocese served members of the Church of the East inArmenia, and its bishops sat atHalat. The diocese is last mentioned in 1281, and probably lapsed in the fourteenth century during the disorders that attended the fragmentation of the Mongol empire.
The East Syriac diocese of Armenia, whose bishops sat in the town ofHalat on the northern shore of Lake Van, is attested between the fifth and fourteenth centuries. In the fifth century the diocese ofHalat was not assigned to a metropolitan province, but was later included in the province ofNisibis, probably shortly after theArab conquest of Persia. The patriarchTimothy I created a short-lived metropolitan province for Armenia, presumably by raising the status of the diocese ofHalat. By the second half of the eleventh centuryHalat was once again a suffragan diocese of the province of Nisibis. By the thirteenth century the jurisdiction of the bishops ofHalat included the towns ofVan and Wastan. The thirteenth-century Nestorian metropolitan Shlemun of Basra, author of theBook of the Bee (c.1222), was a native ofHalat.[1]

The bishop Artashahr of Armenia was among the signatories of the acts of the synod ofDadishoʿ in 424. At this period the diocese, probably based onHalat, was not assigned to a metropolitan province.[2]
The bishopYaʿqob ofHalat, a writer mentioned in the list of Syriac authors compiled in the fourteenth century byʿAbdishoʿ Bar Brikha, flourished during the reign of the patriarchPethion (731–40).
An unnamed bishop of Armenia was present at the consecration of the patriarchʿAbdishoʿ II in 1074.[3]
A note of 1137 by the copyist of theMukhtasar mentions the recent suppression of the metropolitan province ofBardaʿa (in Azerbaijan) and the attribution of responsibility for the remaining Christians in the province to Eliya, bishop ofHalat.[4]
The bishop Yuwanis ofHalat was appointed metropolitan of Kashgar and Nevaketh by the patriarch Eliya III (1176–90).[5]
The bishop Sliba-zkha ofHalat was present at the consecration of the patriarchDenha I in 1265.[6]
The bishopHnanishoʿ ofHalat was present at the consecration of the patriarchYahballaha III in 1281.[7]