5
Byzantine expansion during Justinian's reign.
that he introduced became a highly prized and stable currency), and made changes to the structure of the army. Under Constantine, the Empire had recovered much of its military strength and enjoyed a period of stability and prosperity.
Under Constantine, Christianity did not become the exclusive religion of the state, but enjoyed imperial preference, since the Emperor supported it with generous privileges. Constantine established the principle that emperors should not settle questions of doctrine, but should summon general ecclesiastical councils for that purpose. The Synod of Arles was convened by Constantine, and the First Council of Nicaea showcased his claim to be head of the Church.
The state of the Empire in 395 may be described in terms of the outcome of Constantine's work. The dynastic principle was established so firmly that the emperor who died in that year, Theodosius I, could bequeath the imperial office jointly to his sons: Arcadius in the East and Honorius in the West. Theodosius was the last emperor to rule over the full extent of the empire in both its halves.
The Eastern Empire was largely spared the difficulties faced by the West in the third and fourth centuries, due in part to a more established urban culture and greater financial resources, which allowed it to placate invaders with tribute and pay foreign mercenaries. Theodosius II further fortified the walls of Constantinople, leaving the city impervious to most attacks; the walls were not breached until 1204. To fend off
the Huns of Attila, Theodosius gave them subsidies (purportedly 300 kg (700 lb) of gold). Moreover, he favored merchants living in Constantinople who traded with the Huns and other foreign groups.
His successor, Marcian, refused to continue to pay this exorbitant sum. However, Attila had already diverted his attention to the Western Roman Empire. After he died in 453, his empire collapsed and Constantinople initiated a profitable relationship with the remaining Huns, who would eventually fight as mercenaries in Byzantine armies.
After the fall of Attila, the Eastern Empire enjoyed a period of peace, while the Western Empire collapsed (its end is usually dated in 476 when the Germanic Roman general Odoacer deposed the titular Western Emperor Romulus Augustulus, but declined to replace him with