counter their raids. He was probably the Byzantine commander at the Battle of Mu'tah in 629, the first major encounter of the Muslim Arabs and the Byzantines. In 634, he led his forces from Mesopotamia to Syria, where he apparently suffered a heavy defeat at a battle near Gabitha (perhaps the Battle of Ajnadayn on 30 July, although other sources indicate that he was defeated in October). Thereafter he retreated to Edessa or Antioch, joining Heraclius. During the Byzantine counteroffensive of 636, he re-occupied Emesa and Damascus, which had been abandoned by the Muslims. He most likely did not participate in the final Battle of Yarmouk on 20 August 636, contrary to the reports of Muslim sources (which also record that he was killed there). Instead, his failure to counter the Muslim expeditions caused a rift in his relations with Heraclius; and Theodore allegedly criticized his brother's controversial marriage to his niece Martina. In response, Heraclius recalled Theodore to Constantinople and ordered his son Heraclonas to publicly humiliate and imprison him. This humiliation caused Theodore's son, also named Theodore, to participate in the abortive plot of John Athalarichos to overthrow Heraclius in 637. Theodore's other son, Gregory, is only mentioned in 649, in the dependents of Theophilus of Edessa, such as Theophanes the Confessor. Theophanes mentions that Gregory served as a hostage in the court of Mu'awiya I as part of the terms for the treaty Constans II negotiated with the caliph, but the treaty collapsed in 651 when Gregory died at Helioupolis. References Sources 6th-century births 7th-century deaths 7th-century Byzantine people Byzantine generals Heraclian dynasty Byzantine people of the Arab–Byzantine wars People of the Roman–Sasanian Wars Heraclius Kouropalatai