Editing Marcian (section)

===Reign of Theodosius II===
[[File:Theodosius II Louvre Ma1036 (cropped).jpg|thumb|upright|Emperor [[Theodosius II]]]]
The Eastern Roman Empire was plagued by external threats during the reign of [[Theodosius II]]. In 429, the Vandals, led by [[Gaiseric]], began to conquer [[Africa (Roman province)|Roman Africa]]. Theodosius immediately organized a response, [[Battle of Hippo Regius (431)|sending Aspar and three other commanders to attempt to repel them in the summer of 431]]. To the north, the Huns, who had customarily attacked the empire whenever its armies were preoccupied, withdrawing as those forces returned, sent ambassadors to Theodosius in 431, demanding tribute. He agreed to their demand to pay {{convert|350|lb}} of gold each year. In 434, the Eastern Roman armies were still campaigning against the Vandals in Africa, having faced initial defeats and the withdrawal of many of the Western Roman soldiers. In the face of Eastern Roman weakness, the Huns doubled their demand, asking for {{convert|700|lb}} of gold per year, which Theodosius agreed to. The threat the Huns posed to his weakly protected empire was enough that Theodosius recalled many of his forces from Africa. With large numbers of the Eastern Roman armies home, and [[Attila]], who had just taken power in the Hunnic Confederation, busy campaigning to the north, Theodosius refused to pay the tribute and continued to refuse to until 439.{{sfn|Thompson|1950|pp=60–65}}

On 19 October 439, the Vandals defeated the weakened Eastern Roman armies and captured the major city of [[Carthage]]. Both the Western and Eastern Roman Empires began preparing a massive counter-offensive, stripping the Balkan provinces of protection. In the spring of 440, 1,100 ships set sail from Constantinople for Africa;{{sfn|Thompson|1950|pp=60–65}} sending away so many of the Eastern Roman forces was a huge gamble on Theodosius' part. He was betting the fortified cities along the [[Danube]] could delay the Huns long enough for the invasion force to gain a secure foothold in Africa, allowing troops to be withdrawn back to the northern frontier. This gamble worked until 442 when the bishop of [[Margus (city)|Margus]] led a raiding party into the Huns' territory and desecrated their royal tombs. In response to this desecration, Attila demanded that the bishop be handed over. To ensure his own safety, the bishop struck a deal with Attila, surrendering the city of Margus to him in exchange for his own life. With control of Margus, Attila had a foothold across the Danube, which he aggressively exploited, capturing and destroying the cities of [[Viminacium]], [[Singidunum]], and [[Sirmium]]. Theodosius recalled Aspar to Constantinople and launched a counter-attack. After his force was decisively defeated, Theodosius undertook to pay tribute to the Huns every year, which he did until his death in 450.{{sfn|Thompson|1950|pp=60–78}}