Fortunately for the eastern portion of the Roman world, Anthemius, the statesman at the head of the Government for six years during the minority of Theodosius II., was eminently qualified for his position by lofty character, distinguished ability, and long experience in the public service. When appointed Prætorian Prefect of the East, in 405, by the Emperor Arcadius, Chrysostom remarked that the appointment conferred more honour on the office than upon Anthemius himself; and the ecclesiastical historian Socrates extols the prefect as “one of the wisest men of the age.”[162] Proceeding, therefore, to do all in his power to promote the security of the State, Anthemius cleared the Balkan Peninsula of the hostile Huns under Uldin, driving them north of the Danube. Then, to prevent the return of the enemy, he placed a permanent flotilla of 250 vessels on that river, and strengthened the fortifications of the cities in Illyria; and to crown the system of defence, he made Constantinople a mighty citadel. The enlargement and refortification of the city was thus part of a comprehensive and far-seeing plan to equip the Roman State in the East for the impending desperate struggle with barbarism; and of all the services which Anthemius rendered, the most valuable and enduring was the addition he made to the military importance of the capital. The bounds he assigned to the city fixed, substantially, her permanent dimensions, and behind the bulwarks he raised—improved and often repaired, indeed, by his successors—Constantinople acted her great part in the history of the world. The erection and repair of the fortifications of a city was an undertaking which all citizens were required to assist, in one form or another. On that point the laws were very stringent, and no rank or privilege exempted any one from the obligation to promote the work.[163] One-third of the annual land-tax of the city could be drawn upon to defray the outlay, all expenses above that amount being met by requisitions laid upon the inhabitants. The work of construction was entrusted to the Factions, as several inscriptions on the walls testify. In 447, when the Theodosian fortifications were repaired and extended, the Blues and the Greens furnished, between them, sixteen thousand labourers for the undertaking.[164] The stone employed upon the fortifications is tertiary limestone, brought from the neighbourhood of Makrikeui, where the hollows and mounds formed in quarrying are still visible. The bricks used are from 1 foot 1 inch to 1 foot 2 inches square, and 2 inches thick. They are sometimes stamped with the name of their manufacturer or donor, and occasionally bear the name of the contemporary emperor, and the indiction in which they were made. Mortar, mixed with powdered brick, was employed in large quantities, lest it should dry without taking hold,[165] and bound the masonry into a solid mass, hard as rock.