Artabastos’s usurpation and the initial stage the military reform of Constantine V: 40-s of the 8th century

The article is devoted to the early period of military-administrative reform of Constantine V (741-775). The author considers Constantine V wasn’t the successor Leo III the Isaurian (717-741) military policy. In 742-743 he struggled for the throne. His opponent was Artabastos comes of the Opsikion theme. He was sup-ported by several strategoi of large themes. Constantine V had suppressed the mutiny and started the formation of a mobile army. It consisted of the most battleworthy of regular units. The main part of the regular troops was withdrawn under the jurisdiction of the strategoi of Eastern themes. In the 740-750 Constantine V carried out some successful military campaigns in Northern Syria and Transcaucasia. This proved the effectiveness of regular troops in comparison with detachments of the provincial militias. The author believes the lack of financial resources had been the main obstacle for the fast finishing the military reform