[Sidenote: Character of Constantine V.] To the misfortune of the empire the able and hard-working Constantine died in 685, at the comparatively early age of thirty-six. We hear little that is unfavourable to him from any chronicler: his sole crime seems to have been the cruel act of slitting the noses of his two brothers Heraclius and Tiberius in 680, to disqualify them from holding imperial power. They had hitherto been nominally the colleagues of Constantine, and were honoured with the title of Caesars, but in the interests of his own son Justinian, now a growing boy, the emperor determined to make it impossible for them to aspire to the supreme power. It appears to have been a cruel and unjustifiable act, and unless the Caesars had given provocation, a fact of which we have no hint in any chronicler, it was a grievous blot on the otherwise excellent character of Constantine V. The young Justinian, second of that name, mounted his father’s throne in 685, when only in his seventeenth year. The accession of this prince was a fearful misfortune for the empire. He possessed the qualities of his grandfather Constantinus in an exaggerated form, being arbitrary, cruel, reckless, and high-handed, yet so brave and capable that his throne was not easy to shake. [Sidenote: Justinian II., 685-95.] He started on his career too young, and might have come to better things if his father had lived for another ten years; but, abandoned to his own devices ere he was well out of his boyhood, he developed into a bloodthirsty tyrant. The first few years of his reign, ere he had felt his feet and fully realised his own desires, were comparatively uneventful. The Saracens were occupied in civil wars since the death of Muavia, and gave no trouble: the caliph Abd-el-Melik was only too glad to renew with Justinian the treaty that his predecessor had made with Constantine V. Unmolested by the Saracens, Justinian sent armies into Iberia and Albania, the Christian kingdoms under the Caucasus, and compelled them to pay him tribute. Soon after he undertook in person a great expedition against the Bulgarians, designing to push the Roman boundary once more to the Danube. He was very successful, beating the enemy in the field, and bringing back more than 30,000 captives, from whom he organised an auxiliary force for service in Asia.