fortifications defied the assaults of barbarism upon the civilized
life of the world for more than a thousand years. As might be expected,
the walls demanded frequent restoration from time to time in the course
of their long history. Inscriptions upon them record repairs, for
example, under Justin II., Leo the Isaurian, Basil II., John
Palaeologus, and others. Still, the ramparts extending now from the
Marmora to Tekfour Serai are to all intents and purposes the ruins of
the Theodosian walls of the 5th century.

This is not the case in regard to the other parts of the fortifications
of the city. The walls along the Marmora and the Golden Horn represent
the great restoration of the seaward defences of the capital carried out
by the emperor Theophilus in the 9th century; while the walls between
Tekfour Serai and the Golden Horn were built long after the reign of
Theodosius II., superseding the defences of that quarter of the city in
his day, and relegating them, as traces of their course to the rear of
the later works indicate, to the secondary office of protecting the
palace of Blachernae. In 627 Heraclius built the wall along the west of
the quarter of Aivan Serai, in order to bring the level tract at the
foot of the 6th hill within the city bounds, and shield the church of
Blachernae, which had been exposed to great danger during the siege of
the city by the Avars in that year. In 813 Leo V. the Armenian built the
wall which stands in front of the wall of Heraclius to strengthen that
point in view of an expected attack by the Bulgarians.

The splendid wall, flanked by nine towers, that descends from the court
of Tekfour Serai to the level tract below Egri Kapu, was built by Manuel
Comnenus (1143-1180) for the greater security of the part of the city in
which stood the palace of Blachernae, then the favourite imperial
residence. Lastly, the portion of the fortifications between the wall of
Manuel and the wall of Heraclius presents too many problems to be
discussed here. Enough to say, that in it we find work belonging to the
times of the Comneni, Isaac Angelus and the Palaeologi.

If we leave out of account the attacks upon the city in the course of
the civil wars between rival parties in the empire, the fortifications
of Constantinople were assailed by the Avars in 627; by the Saracens in
673-677, and again in 718; by the Bulgarians in 813 and 913; by the
forces of the Fourth Crusade in 1203-1204; by the Turks in 142