Basil was born probably early in the twelfth century, although he is described as an elderly man when he took over the diocese of Edessa. His brother Michael bar Shumna headed the administration of the city of Edessa under Count Joscelin II. By 1129, Basil was an ordained priest and bishop of Qaysūn. Patriarch John XI was living in Qaysūn at that time and considering making it his permanent residence. Growing disillusioned with ecclesiastical politics, Basil withdrew from Qaysūn to a monastery. In 1143, Joscelin transferred Basil to Edessa from the diocese of Qaysūn. He was accused of having obtained the vacant see illegitimately, since Joscelin II was a Catholic who had no authority to transfer Syriac bishops and who had acted without the knowledge of Patriarch Athanasius VII. Basil denied the accusation in a letter to the patriarch. Joscelin and the patriarch were later reconciled. At the start of the Siege of Edessa in November 1144, Basil joined with his Catholic and Armenian counterparts, Bishops Hugh and John, to organize the defence of the city. He persuaded Hugh to seek a truce, but the offer did not reach the besieging Turkish commander, Zengi. During the two days of looting and massacre that followed the breaching of the walls on 24 December, Basil had himself led about on a rope, naked and with his beard shaven. Zengi encountered him when he entered the city after the two days. In Zengi's tent, Basil impressed the commander with his humility, courage and fluency in Arabic. Zengi had him dressed and the two of them discussed the rebuilding of the city. According to Michael the Great, "as long as Zengi ruled in Edessa this venerable bishop was very influential." Basil was responsible for repopulating the city. After the death of Zengi in 1146, Joscelin forced Basil to assist him in his effort to retake the city. When this failed and the city fell to Nur al-Din, Basil fled to Samosata. Having been accused of treason by the Edessenes for his close collaboration with Zengi, he was imprisoned in Hromgla by Joscelin. He remained in prison for three years. It was during this period that he began writing his history of the city. When Joscelin was captured by the Turks in 1150, it was Basil who had heard his last confession. He died in captivity nine years later. Basil died in 1169 or 1171.
Writings
Basil was a well-placed eyewitness to many of the events he wrote about. The purpose of his work was theodical as well as historical. He sought to provide an explanation for the disasters that had befallen Edessa in his lifetime consistent with God's plan. He identified Edessa with the biblical Ur of the Chaldees, reading its Syriac name, Urhay, as a combination of words meaning city and Chaldees. Michael the Great uses Basil for the years 1118–1143. The anonymous author of the Chronicle of 1234 frequently cites Basil for the period after 1144. Most of his material on Edessa originates with Basil. He is clear that he is abridging Basil's longer account. He is also clear that he disagrees with Basil's sharp condemnation of his own flock. Aphram Barsoum hypothesized that Basil wrote a short treatise on the Byzantine emperor John II's defeat of a Cuman invasion in 1122. This is based on extracts found in Michael the Great and it is possible that the information was found in Basil's Edessene chronicle. The existence of About the Cumans remains hypothetical. Three dodecasyllabic poems on the fall of Edessa in 1144 have been attributed to Basil.
