For much of the nineteenth and twentieth centuries the district of Salmas in northwest Iran was an archdiocese of the Chaldean Catholic Church, now apart of the Chaldean Catholic Archeparchy of Urmyā.
In the East Syrian tradition the martyrdom of the apostle Bartholemew has traditionally been placed at Salmas. Although there were East Syrian Christians in the Salmas district at least as early as the seventh century, Salmas is not heard of as the seat of an East Syrian bishop until 1281, when its bishop Joseph attended the enthronement of Mar Yaballaha III.
The church of the village of Chara in the Salmas district was built in 1360 at the expense of Mar Sliba, probably the bishop of Salmas. Interestingly, the name Sliba was taken at a later period by the bishops of Jilu, a district with which Salmas was linked in the sixteenth century.
The Salmas district was inhabited by both Nestorian and Armenian Christians, and around the end of the thirteenth century had both a Nestorian and an Armenian bishop. During the fifteenth century a number of Latin bishops were appointed for Salmas, though they may have been titular bishops only. Only the Nestorian bishopric seems to have survived into the sixteenth century.
An unnamed bishop of Salmas was one of only three remaining Nestorian bishops in 1551. Salmas is listed by ʿAbdishoʿ IV Maron in 1562 as a metropolitan see, with suffragans at 'Baumar' (apparently a village in the Salmas plain), 'Sciabathan' (possibly Shapat, the Shemsdin district) and 'Vastham' (possibly Vastan on the shore of Lake Van). ʿAbdishoʿ’s letter stated that these and other bishoprics were in Persian territory.