In Rome, Hostilian, son of Decius, succeeds his father, while Trebonianus Gallus is proclaimed Emperor by the troops. Gallus accepts him as co-emperor, but an outbreak of plague strikes the city and kills the young Hostilian.
Battle of Barbalissos: King Shapur I defeats a Roman field army at Barbalissos in Syria (probable date, could have been in 253). The size of the Roman field army is claimed by Persian sources to have been 70,000 men strong, yet this is unlikely.
Aemilianus is proclaimed "enemy of the State" by the Roman Senate. Trebonianus Gallus is defeated at Interamna Nahars (Umbria); he flees with Volusianus to the north, but at Foligno they are killed by their own troops.
Aemilianus rules for 3 months the Roman Empire; he promises to fight in Thrace and goes to war against Persia. The Senate gives him the rank of Pontifex Maximus.
Valerianus I splits the Roman Empire in two; Gallienus taking control of the West and his father ruling the East, where he faces the Persian threat.
Battle of Barbalissos: King Shapur I, defeats a Roman field army at Barbalissos in Syria (probable date, could have been in 252). The size of the Roman field army has been thought to be 70,000 men strong, yet this is unlikely.
The Roman Empire is threatened by several peoples on their borders: the Germanic confederations, such as the Franks on the Middle Rhine, the Alemanni on the upper Rhine and Danube, and the Marcomanni facing the provinces at Noricum and Raetia. On land the confederation of Goths threaten the lower Danube provinces and on the sea they threaten the shores of Thracia, Bithynia et Pontus, and Cappadocia. In the eastern provinces, the Sassanid Persians had the previous year defeated a Roman field army at Barballisos and afterwards plundered the defenseless provinces. This was the period of time which today is called the crisis of the third century.
Valerian's persecution of Christians begins: his edict orders bishops and priests to sacrifice according to the pagan rituals, and prohibits Christians, under penalty of death, from meeting at the tombs of their deceased.
A second Imperial edict prohibits Christianity in the Roman Empire. This edict divides Christians into four categories: priests, who are to be put to death; senators and equestrians, who are to be stripped of their positions and their property confiscated; nuns, who are to be exiled; and imperial civil servants, who are condemned to forced labour.