Editing Constantinople (section)

=== 337–529: Constantinople during the Barbarian Invasions and the fall of the West ===
{{see also|Palace of Lausus}}
[[File:Istambul_cokol1RB.JPG|thumb|[[Theodosius I]] was the last [[Roman emperor]] who ruled over an undivided empire (detail from the Obelisk at the [[Hippodrome of Constantinople]]).]]
[[File:Bozdoģan_Kemeri_-_panoramio.jpg|thumb|280px|[[Aqueduct of Valens]], completed by Roman emperor Valens in the late 4th century AD]]

The importance of Constantinople increased, but it was gradual. From the death of Constantine in 337 to the accession of [[Theodosius I]], emperors had been resident only in the years 337–338, 347–351, 358–361, 368–369. Its status as a capital was recognized by the appointment of the first known Urban Prefect of the City Honoratus, who held office from 11 December 359 until 361. The urban prefects had concurrent jurisdiction over three provinces each in the adjacent dioceses of Thrace (in which the city was located), Pontus and Asia comparable to the 100-mile extraordinary jurisdiction of the prefect of Rome. The emperor [[Valens]], who hated the city and spent only one year there, nevertheless built the Palace of [[Hebdomon]] on the shore of the [[Sea of Marmara|Propontis]] near the [[Golden Gate (Constantinople)|Golden Gate]], probably for use when reviewing troops. All the emperors up to [[Zeno (emperor)|Zeno]] and [[Basiliscus]] were crowned and acclaimed at the Hebdomon. Theodosius I founded the [[Studion|Church of John the Baptist]] to house the skull of the saint (today preserved at the [[Topkapı Palace]]), put up a memorial pillar to himself in the Forum of Taurus, and turned the ruined temple of [[Aphrodite]] into a coach house for the [[Praetorian prefecture of the East|Praetorian Prefect]]; [[Arcadius]] built a new forum named after himself on the Mese, near the walls of Constantine.

After the shock of the [[Battle of Adrianople]] in 378, in which Valens and the flower of the Roman armies were destroyed by the [[Visigoths]] within a few days' march, the city looked to its defences, and in 413–414 [[Theodosius II]] built the 18-metre (60-foot)-tall [[Walls of Constantinople|triple-wall fortifications]], which were not to be breached until the coming of gunpowder. Theodosius also founded a [[University of Constantinople|University]] near the Forum of Taurus, on 27 February 425.

[[Uldin]], a prince of the [[Huns]], appeared on the Danube about this time and advanced into Thrace, but he was deserted by many of his followers, who joined with the Romans in driving their king back north of the river. Subsequent to this, new walls were built to defend the city and the fleet on the Danube improved.
[[File:Istanbul_Mosaic_Museum_dec_2016_1608.jpg|thumb|left|upright=1.15|Mosaics of the [[Great Palace of Constantinople]], now in [[Great Palace Mosaic Museum]] in [[Istanbul]]]]

After the [[barbarian]]s overran the Western Roman Empire, Constantinople became the indisputable capital city of the Roman Empire. Emperors were no longer peripatetic between various court capitals and palaces. They remained in their palace in the Great City and sent generals to command their armies. The wealth of the eastern Mediterranean and western Asia flowed into Constantinople.