Six years later (711) there was a more terrible tragedy. Justinian was justly dethroned and slain, and his little boy Tiberius, the child of his exile, was torn from the church of the Theotokos at Blachernae and cruelly butchered outside the palace wall. The next years were stained by crimes and follies hardly less revolting than those that had gone before; there could be no more bitter irony than the single word which the humble tax-gatherer, who was elevated against his will to the imperial throne under the name of Theodosius II., inscribed upon his tomb--ὑγίεια--health was to be found nowhere for the empire in his day. His successor, Leo the Isaurian, whom the Senate and the patriarch of Constantinople chose in 718 to be their lord, had seen an adventurous life, and was already the general and imperator of the great eastern army. His first task was to defend the city against the Saracens. The great siege of 718, lasting twelve months, failed chiefly through his skill and patience. The invaders encamped before the city in August 717; the name of their Suleiman was one which was later to be very familiar to the Byzantines. When winter came it was one of those bitter seasons to which Constantinople is often subject. For many weeks snow lay on the ground, and the besiegers suffered far more than the garrison. Leo defended the city with extraordinary skill, and at length, at the right moment, by a well planned sortie he scattered the infidels, and of the great host of a hundred and eighty thousand men the Mohammedan historians say that only thirty thousand escaped back to the East. No greater feat was ever performed by the great empire, the bulwark of Christendom, than this heroic defence and splendid repulse. It was not wholly the work of Leo, for the Bulgarians came from the north to his aid, and a pestilence, even before the storms of the Dardanelles destroyed their fleet, caused the withdrawal of the Saracen host. Then as an administrator he reformed the government, as a legist he reissued and revised the laws. The great earthquake of 739 caused the institution of a new tax, if not a new financial system. "Some of the oldest monuments in the city were thrown down by the shock, the statue of Constantine the Great, at the gate of Attalus; the statue and sculptured column of Arcadius; the statue of Theodosius I., over the Golden Gate, and the church of Irene, close to S. Sophia. The land walls of the city were also subverted; and in order to repair the fortifications Leo increased the taxes by one-twelfth, or a miliarision in a nomisma."