TheodosiusII(401–450)

The diplomacy of Theodosius II (401–450) was mostly determined by two fronts: Persia on the east, and the Huns in the Balkans. Confrontations with the Vandals in Africa, though occasionally requiring East Roman military presence, mostly remained the responsibility of the West Roman government. Relations with Persia throughout the reign of Theodosius II were mainly peaceful, military conflicts were short and relatively successful for the Romans, while diplomatic efforts were focused on safeguarding the safety of groups of Christians under Persian control. An agreement to share the financial burden of defending the passes in the Caucasian Mountains from nomadic raids was reached between Theodosius II and Yazdagard II.The Hunnic front was the major challenge for East Roman diplomacy. Agreements with the dangerous Hun empire forced the Romans to make payments to keep the peace. Continuing threats to the Balkans and the increasing demands of Attila resulted in an unsuccessful assassination attempt on the Hun leader. When clandestine diplomacy failed, Theodosius had to act flexibly, adjusting the rules and acknowledging an important shift in priorities, placing the Huns at the forefront of imperial partners.