Abgar V

Abgar V (died c. AD 50), called Ukkāmā (meaning "the Black" in Syriac and other dialects of Aramaic), was the King of Osroene with his capital at Edessa.
Life.
Abgar was described as "king of the Arabs" by Tacitus, a near-contemporary source. According to Movses Khorenatsi, Abgar was an Armenian. Yet both Robert W. Thomson and Richard G. Hovannisian state Abgar's Armenian ethnicity was invented by Khorenatsi. Modern scholarly consensus agree that the Abgarids were in fact an Arab dynasty. 
Abgar V came to power in 4 BC. He became a Roman client, lost his throne in 7 AD and regained it five years later.
Armenian historian Movses Khorenatsi, or Moses of Chorene (ca. 410–490s AD), reported that the chief wife of King Abgar V was Queen Helena of Adiabene, the wife of King Monobaz I of Adiabene, and thus the kingdoms of Edessa and Adiabene were linked in some manner. Robert Eisenman suggests Queen Helena as one of the wives of King Abgar V, who allotted her the lands of Adiabene. Professor Eisenman derived this association from Movses Khorenatsi mentioning the same famine relief to Judaea as does Flavius Josephus:
Professor Eisenman goes on to equate King Abgarus V with the Agabus in Acts of the Apostles (Acts 11:27-30), because Agabus was identified with the same famine relief as Queen Helena. By necessity Eisenman then equates the biblical Antioch Orontes with Antioch Edessa, indicating that Paul the Apostle and Barnabas went to Edessa.
Christian legend.
Letter of Abgar to Jesus.
Abgar V is claimed to be one of the first Christian kings in history, having been converted to the faith by Thaddeus of Edessa, one of the seventy disciples.
The church historian Eusebius records that the Edessan archives contained a copy of a correspondence exchanged between Abgar of Edessa and Jesus. The correspondence consisted of Abgar's letter and the answer dictated by Jesus. On August 15, 944, the Church of St. Mary of Blachernae in Constantinople received the letter and the Mandylion. Both relics were then moved to the Church of the Virgin of the Pharos.
The account of this enjoyed great popularity in the East, and also in the West, during the Middle Ages: Jesus' letter was copied on parchment, inscribed in marble and metal, and used as a talisman or an amulet. Of this correspondence, there survive not only a Syriac text, but an Armenian translation as well, two independent Greek versions, shorter than the Syriac, and several inscriptions on stone.
A curious growth has arisen from this event, with scholars disputing whether Abgar suffered from gout or from leprosy, whether the correspondence was on parchment or papyrus, and so forth.
The text of the letter was:
Jesus gave the messenger the reply to return to Abgar:
Egeria wrote of the letter in her account of her pilgrimage in Edessa. She read the letter during her stay, and remarked that the copy in Edessa was fuller than the copies in her home (which was likely France).
In addition to the importance it attained in the apocryphal cycle, the correspondence of King Abgar also gained a place in liturgy for some time. The Syriac liturgies commemorate the correspondence of Abgar during Lent. The Celtic liturgy appears to have attached importance to it; the "Liber Hymnorum", a manuscript preserved at Trinity College, Dublin (E. 4, 2), gives two collects on the lines of the letter to Abgar. It is even possible that this letter, followed by various prayers, may have formed a minor liturgical office in some Catholic churches.
This event has played an important part in the self-definition of several Eastern churches. Abgar is counted as saint, with feasts on May 11 and October 28 in the Eastern Orthodox Church, August 1 in the Syrian Church, and daily in the Mass of the Armenian Apostolic Church. The Armenian Apostolic Church in Scottsdale, Arizona, is named after Saint Abgar (also spelled as Apkar).
Critical scholarship.
The scholar Bart D. Ehrman cites evidence from Han Drijvers and others for regarding the whole correspondence as forged in the third century by orthodox Christians "as an anti-Manichaean polemic", and entirely spurious.
A number of contemporary scholars have suggested origins of the tradition of Abgar's conversion apart from historical record. S. K. Ross suggests the story of Abgar is in the genre of a genealogical myth which traces the origin of a community back to a mythical or divine ancestor. F. C. Burkitt argues that the conversion of Edessa at the time of Abgar VIII was retrojected upon the Apostolic age. William Adler suggests the origin of the story of the conversion of Abgar V was an invention of an antiquarian researcher employed by Abgar VIII, who had recently converted to Christianity, in an effort to securely root Christianity in the history of the city. Walter Bauer, on the other hand, argued the legend was written without sources to reinforce group cohesiveness, orthodoxy, and apostolic succession against heretical schismatics. However, several distinct sources, known to have not been in contact with one another, claimed to have seen the letters in the archives, so his claim is suspect.
Significant advances in scholarship on the topic have been made by Desreumaux's translation with commentary, M. Illert's collection of textual witnesses to the legend, and detailed studies of the ideology of the sources by Brock, Griffith, and Mirkovic. The majority of scholars now claim the goal of the authors and editors of texts regarding the conversion of Abgar were not so much concerned with historical reconstruction of the Christianisation of Edessa as the relationships between church and state power, based on the political and ecclesiological ideas of Ephraem the Syrian. However, the origins of the story are far still from certain, although the stories as recorded seem to have been shaped by the controversies of the third century CE, especially as a response to Bardaisan.