mission · 35 · Edessa
Eusebius says he found in the archives of Edessa, in Syriac, a letter from King Abgar the Black to Jesus asking to be healed, and a reply promising to send a disciple after the Ascension; and that Thaddeus, one of the seventy, came and healed him (HE 1.13). The documents are not authentic and have not been thought so for a long time. What is real is that Edessa had them in its archives by the early fourth century and built its self-understanding on them, and that Syriac Christianity is genuinely very old. The identity is the knot: Eusebius calls this Thaddeus one of the seventy, the Syriac tradition calls him Addai, and the Western calendars merge him with Jude the son of James of the Twelve. This dataset hangs the event on Jude because that is who the calendars commemorate, and says here that Eusebius does not.
To carry the gospel to a king who had written asking for it.
A church at Edessa that traced itself to an apostle, and the Syriac tradition's founding charter.