Jacob Baradaeus

Jacob Baradaeus (/ˌbærəˈdiːəs/; Syriac: ܝܥܩܘܒ ܒܘܪܕܥܝܐ, romanized: Yaʿqub Burdʿoyo; Greek: Ἰάκωβος Βαραδαῖος; Arabic: مار يعقوب البرادعي), also known as Jacob bar Addai or Jacob bar Theophilus, was the Bishop of Edessa from 543/544 until his death in 578. He is venerated as a saint in the Oriental Orthodox Churches and his feast day is 31 July. Jacob's missionary efforts helped the non-Chalcedonian Syriac Orthodox Church survive despite persecution, for which it came to bear the name of "Jacobite" Church after its eponymous leader.