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 much of the populace was moved to the region of Cyzicus under Justinian: Tiberius successfully negotiated with Abd al-Malik in 698/699 to allow the Cypriots who had been moved to Propontis, and those who had been captured by the Arabs and brought to Syria, to return to their homelands, as well as strengthened the garrison of the island with Mardaite troops from the Taurus Mountains. 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 Philippikos Bardanes, the son of a patrician, to the island of Cephalonia, according to Byzantine chronicler Theophanes the Confessor he was exiled for spreading word that he had had a dream in which he was emperor.