Rabbula (or Rabbulas) was a bishop of Edessa from 411 to August 435 AD, noteworthy for his opposition to the views of Theodore of Mopsuestia, as well as those of Nestorius. However, his successor Ibas, who was in charge of the school of Edessa, reversed the official stance of that bishopric. Rabbula is not to be confused with the otherwise unknown scribe of the 6th century Rabbula Gospels.
Early life 
He was a native of Kenneschrin, a town some few miles south of Aleppo and the seat of a bishopric. His father was a pagan priest, and though his mother was a devoted Christian he remained a pagan until some time after his marriage. During a journey to his country estates he was converted to Christianity partly through coming in contact with a case of miraculous healing and partly through the teaching and influence of Eusebius, bishop of Kenneschrin, and Acacius, bishop of Aleppo.
Christian asceticism 
With all the energy of his fiery nature he threw himself into the practice of Christian asceticism, sold all his possessions, and separated from his wife and kinspeople. He resided for some time in a monastery, and then passed to a life of greater hardship as a solitary hermit. On the death of Diogenes, bishop of Edessa, in the year 411-412 Rabbula was chosen his successor, and at once accepted the position offered him, without any of the customary show of reluctance.
As a bishop Rabbula was marked by extraordinary energy, by the continued asceticism of his personal life, by his magnificent provision for all the poor and suffering in his diocese, by his care for discipline among the clergy and monks who were under his authority, and latterly by the fierce determination with which he combated all heresies and especially the growing school of the followers of Nestorius, the Archbishop of Constantinople. On one occasion he visited Constantinople and there preached before Theodosius II (who was then favorable to Nestorius) and a great congregation a sermon in denunciation of Nestorian doctrine, of which a portion survives in the Syriac version.
It has been argued by some scholars that this positive picture of Rabbula is not altogether accurate. According to the Life of Rabbula, immediately before becoming bishop of Edessa, Rabbula, in consort with another monk, Eusebius, the future bishop of Tella, went to Baalbek (Heliopolis) in Lebanon (Phoenicia Libanensis), one of the last areas with pagans in order to seek martyrdom by provoking the pagans. Rather than being killed, he was severely beaten. The Life of Rabbula claims that Rabbula was preserved from death on account of his destiny to hold the episcopate. This is exactly the sort of suicidal behavior condemned by Augustine in City of God.
Rabbula became a friend of Cyril of Alexandria, with whom he corresponded, and whose treatise De recta fide he translated into Syriac. After a twenty-four year career as bishop, he died in August 435, and was succeeded by Ibas.
The literary legacy of Rabbula is small in bulk, and is mostly to be found in Overbeck. Perhaps his primary importance to the historian of Syriac literature lies in the zeal with which he strove to replace the Diatessaron or Gospel Harmony of Tatian with the four canonical Gospels, ordering that a copy of the latter should be placed in every church.
The version survives in a British Museum manuscript. According to his biographer  he himself produced a version (or revision) of the New Testament in Syriac, known as the Peshitta. Rabbula's involvement may have been, a first step in the direction of the Philoxenian version. FC Burkitt went further and advanced the hypothesis that Rabbula, at least as regards the Gospels, actively helped in the translation of the current Peshitta text, using the Greek text as read in Antioch about 400. However, since then Arthur Vöörbus has furnished evidence that the Peshitta predated Rabbula.
See also 
- Alexius of Rome, lived by begging during the episcopate of Bishop Rabbula.
- Jan Willem Drijvers, "The Protonike Legend, the Doctrina Addai and Bishop Rabbula of Edessa," Vigiliae Christianae 51 (1997), 298-315.
- Overbeck, pp. 239-244.
- see Wright's Syr. Lit. p. 9
- (Overbeck, p. 172)
- as Wright suggests (Syr. Lit. p. II)
- Vöörbus (1947). Investigations into the Text of the New Testament used by Rabbula of Edessa.
- "Rabbulas". Catholic Encyclopedia. New York: Robert Appleton Company. 1913.
- Entry in ‘Catholic Encyclopedia’ on Rabbulas. Website newadvent.org.
- Overbeck, "S. Ephraemi Syri, Rabulae Episc. Edesseni, Balæei aliorumque opera selecta" (Oxford, 1865)