Europe 422: Persian War of 421–422
In 421 the Eastern Roman Empire invaded the Sasanian Persian Empire in reprisal for Shah Bahram V’s anti-Christian and anti-Roman policies. The war lasted into early 422, when the Romans agreed to peace in order to deal with a Hunnic invasion of Thrace.
421–422 Roman–Persian War▲
In 420 the young Bahram V gained the throne of the Sasanian Persian Empire and embarked on a number of anti-Roman policies, including persecuting Christians, retaining hired Roman laborers, and attacking merchants. Angered, the Eastern Roman emperor Theodosius II—under the encouragement of his pious sister empress Pulcheria—order the invasion of Persia, and in 421 his forces ravaged Arzanene and threatened Nisibis. In retaliation, Bahram marched into Roman Mesopotamia and besieged Theodosiopolis (Ras al-Ayn), but was repulsed. By this point Theodosius had become concerned by the threat of the Huns, and in early 422 the Romans made peace with the Persians on the condition that both empires tolerate each other’s religion.
421? Hunnic occupation of Pannonia▲
At some point between the fall of Stilicho (408) and the early 420s the Huns crossed the Danube and seized control of the Western Roman provinces of Valeria and Pannonia Prima. It is likely this region was already deeply destabilized after decades of raids by the Huns and their allies.
At some point in the early 420s the Salian Franks seem to have risen up against Roman domination. This revolt was traditionally associated with Pharamond—claimed to be the first king of the Franks—but by the late 19th century it had been shown that Pharamond was a legendary figure whose first mention was in a faulty 7th century genealogy.
421–422? First Perso-Kidarite War▲
While Shah Bahram V of Sasanian Persia was engaged fighting the Romans in the west (421–422), the Kidarite Huns crossed the Oxus river and invaded northeast Persia. After capturing the wealthy city of Merv, they raided deep into Persia, advancing as far westwards as Ray. Unable to deal with this new threat while the Roman war was underway, Bahram begrudgingly agreed to pay tribute to the Kidarites to bring their incursions to an end.
421? Romane gesomnodon▲
According to the tradition of a Roman return to Britain in c. 418, the Romans soon decided that continuing to protect the island was “too troublesome” and, after supplying the Britons with weapons and training manuals, withdrew to Gaul for good in c. 421. During this departure, the Romans allegedly gathered all the treasures of Britain, burying some of it in the hope of a later return and carrying the rest with them across the Channel (a story which is given some credence by the discovery of numerous fifth-century British hoards in the south and east of Britain).
421–422 Rugila’s invasion of Thrace▲
In the winter of 421/422, while most of the Eastern Roman army was deployed on the Persian front, the Hunnic king Rugila led his forces across the Danube into the Prefecture of Illyricum. Easily overwhelming the Gothic garrison posted to defend the Succi Pass, the Huns proceeded to ravage Thrace in early 422 and at one point even threatened to besiege Constantinople. Emperor Theodosius II responded by making peace with Persia and some time around March, with Roman troops returning to the capital, persuaded Rugila to withdraw in return for an annual payment of 350 pounds of gold.