Daylam, also known in the plural form Daylaman (and variants such as Dailam, Deylam, and Deilam), was the name of a mountainous region of inland Gilan,

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkm ...

. It was so named for its inhabitants, known as the

Daylamites The Daylamites or Dailamites (Middle Persian: ''Daylamīgān''; fa, دیلمیان ''Deylamiyān'') were an Iranian people inhabiting the Daylam—the mountainous regions of northern Iran on the southwest coast of the Caspian Sea, now comprisin ...

. The

Church of the East The Church of the East ( syc, ܥܕܬܐ ܕܡܕܢܚܐ, ''ʿĒḏtā d-Maḏenḥā'') or the East Syriac Church, also called the Church of Seleucia-Ctesiphon, the Persian Church, the Assyrian Church, the Babylonian Church or the Nestorian C ...

established a

metropolitan diocese A metropolis religious jurisdiction, or a metropolitan archdiocese, is an episcopal see whose bishop is the metropolitan bishop or archbishop of an ecclesiastical province. Metropolises, historically, have been important cities in their provinces ...

for Daylam and Gilan around 790 under Shubhalishoʿ., p. 166.

See also