Abgar, a name or title borne by a line of kings or toparchs, apparently twenty-nine in number, who reigned in Osrhoene and had their capital at Edessa about the time of the Christian era. According to an old tradition, one of these princes, perhaps Abgar V (Ukkama or Uchomo, 'the black'), being afflicted with leprosy, sent a letter to Jesus, acknowledging his divinity, craving his help and offering him an asylum in his own residence, but Jesus wrote a letter declining to go, promising, however, that after his ascension he would send one of his disciples.
These letters are given by Eusebius (Eccl. Hist. i. 13), who declares that the Syriac document from which he translates them had been preserved in the archives at Edessa from the time of Abgar. Eusebius also states that in due course Judas, son of Thaddaeus, was sent (in 340 = A.D. 29). In another form of the story, derived from Moses of Chorene, it is said further that Jesus sent his portrait to Abgar, and that this existed in Edessa (Hist. Armen., ed. W. Whiston, ii. 29-32). Yet another version is found in the Syriac Doctrina Addaei (Addaeus = Thaddaeus), edited by G. Phillips (1876). Here it is said that the reply of Jesus was given not in writing, but verbally, and that the event took place in 343 (A.D. 32). Greek forms of the legend are found in the Ada Thaddaei (C. Tischendorf, Ada apostolorurf. apocr. 261 ff.).
These stories have given rise to much discussion. The testimony of Augustine and Jerome is to the effect that Jesus wrote nothing. The correspondence was rejected as apocryphal by Pope Gelasius and a Roman Synod (c. 495), though, it is true, this view has not been shared universally by the Roman church (Tillemont, Memoires, i. 3, pp. 990 ff.). Amongst Evangelicals the spuriousness of the letters is almost generally admitted. Lipsius (Die Edessenische Abgar sage, 1880) has pointed out anachronisms which seem to indicate that the story is quite unhistorical. The first king of Edessa of whom we have any trustworthy information is Abgar VIII, bar Ma'nu (A.D. 176-213). It is suggested that the legend arose from a desire to trace the christianizing of his kingdom to an apostolic source.
Being the entry for ABGAR in the 1911 Encyclopedia Britannica, the text of which lies within the public domain.