with an army to retake the city, which John accomplished after launching a surprise attack on its harbor. Despite this initial success, the city was swiftly retaken by Umayyad reinforcements, which forced John to retreat to Crete to regroup. A group of officers who feared Leontiuss wrath for failing to recapture Carthage killed John, and declared Apsimar emperor. Apsimar took the regnal name Tiberius; During this period, the selection of a regnal name was quite common, but later fell out of favor. Tiberius gathered a fleet and allied himself with the Greens (one of the Hippodrome factions), before sailing for Constantinople, which was enduring an outbreak of the bubonic plague. Tiberius and his troops landed at the port of Sykai on the Golden Horn, and then proceeded to lay siege to the city. After several months of siege, the gates of Constantinople were opened for Tiberiuss forces by members of the Green faction, allowing Tiberius to seize the city and depose Leontius; however, this surrender did not prevent his troops from plundering the city. Tiberius had Leontiuss nose slit, and sent him to live in the Monastery of Psamathion in Constantinople. According to the 12th-century chronicler Michael the Syrian, himself citing an unnamed contemporary Syriac source, Tiberius justified his coup by pointing to Leontius' own dethroning of Emperor Justinian II ( for mismanaging the empire as precedent. Tiberius was the first naval officer to assume the throne, partly because Byzantines considered the army far more prestigious. Rule Tiberius was crowned by Patriarch Callinicus shortly after seizing control of Constantinople and deposing Leontius. Once in power, Tiberius did not attempt to retake Byzantine Africa from the Umayyads but rather focused his attention upon the eastern border of his empire. Tiberius appointed his brother, Heraclius, as (a prestigious courtly title) and (head general) of the Anatolian themes. Heraclius invaded the Umayyads in late autumn of 698, crossing the mountain passes of the Taurus Mountains into Cilicia before marching for northern Syria. Heraclius defeated an Arab army sent from Antioch, then raided as far as Samosata before pulling back to the safety of Byzantine lands in spring of 699. Heraclius' military successes led to a series of punitive Arab attacks, with the Umayyad generals Muhammad ibn Marwan and Abdallah ibn Abd al-Malik launching a string of campaigns that conquered the remainder of Byzantine Armenia, which Heraclius was unable to effectively respond to. However,