the Armenians launched a large revolt against the Umayyads in 702, requesting Byzantine aid. Abdallah ibn Abd al-Malik launched a campaign to reconquer Armenia in 704 but was attacked by Heraclius in Cilicia. Heraclius defeated the Arab army of 10,000–12,000 men led by Yazid ibn Hunayn at Sisium, killing most and enslaving the rest; however, Heraclius was not able to stop Abdallah ibn Abd al-Malik from reconquering Armenia. Tiberius attempted to strengthen the Byzantine military by reorganizing its structure, as well as reorganizing the Cibyrrhaeotic Theme, and repairing the sea walls of Constantinople. Tiberius also focused his attention on the island of Cyprus, which had been underpopulated since many of the inhabitants were moved to the region of Cyzicus under Justinian II: Tiberius successfully negotiated with Abd al-Malik in 698/699 to allow the Cypriots who had been moved to Cyzicus, and those who had been captured by the Arabs and brought to Syria, to return to their homelands. He also strengthened the garrison of the island with Mardaite troops from the Taurus Mountains. According to the historian Warren Treadgold, Tiberius attempted to contain the Arabs at sea by way of creating new military provinces, with the creation of the Theme of Sardinia and separating the Theme of Sicily from the Exarchate of Ravenna. Tiberius also banished the future emperor Philippicus, the son of a , to the island of Cephalonia. In 693 Justinian II escaped from Cherson and gained the support of Khagan Busir, leader of the Khazars, who gave Justinian II his sister Theodora as a bride, and welcomed him to his court in Phanagoria. In 703 reports that Justinian II was attempting to gain support to retake the throne reached Tiberius, who swiftly sent envoys to the Khazars demanding that Justinian II be handed over to the Byzantines, dead or alive. Justinian II eluded capture, and sought the support of the Bulgar Khan Tervel. In 705 Justinian II led an army of Slavs and Bulgars to Constantinople and laid siege to it for three days before scouts discovered an old and disused conduit that ran under the walls of the city. Justinian II and a small detachment of soldiers used this route to gain access to the city, exiting at the northern edge of the wall near the Palace of Blachernae, and quickly seizing the building. Tiberius fled to the city of Sozopolis in Bithynia, and eluded his