By place Roman Empire •
Battle of Edessa: With a large army, said to number 70,000 men,
Valerian attempts to drive the Persians back from Edessa. The Roman army is surrounded and most of its troops are killed or captured. Valerian is taken prisoner for the remainder of his life. • King
Shapur I captures Valerian. • King Shapur I sends Valerian to
Bishapur and uses the captured
Roman army for engineering plans. They construct the
Band-e Kaisar ("Bridge of Valerian"). •
Gallienus becomes the sole emperor of
Rome; during his reign the
Pannonian governor
Ingenuus revolts on the
Danube. • Gallienus evacuates the
fortifications (
limes) in the
Agri Decumates (
Germania Superior), covering the
Black Forest area in the face of invading
Alamanni. • Gallienus establishes himself at
Mediolanum (modern
Milan); he reorganizes the army, supported by elite
cavalry, and dispatches troops to the
Rhine frontier. •
Postumus, Roman
usurper, forms the
Gallic Empire and protects the Rhine against an invasion of
Germanic tribes. •
Saloninus, son of Gallienus, is proclaimed
Augustus by his troops. Postumus besieges
Cologne, where
Silvanus is
praetorian prefect and Roman ruler of
Gaul. • Postumus executes Saloninus and his adviser Silvanus after breaching the walls of Cologne. He is recognized as emperor and establishes his capital at
Trier. • Postumus wins over all the
Roman provinces west of the
Alps, including Gaul,
Britain and
Hispania. • The Roman
fort of
Wiesbaden (
Germany) is captured by the Alamanni. • The
Franks take control over the
Scheldt estuary (approximate date).
Persia •
Persian king
Shapur I destroys
Caesarea Mazaca in
Asia Minor.
China • Emperor
Cao Mao of
Former Wei state attempts to lead a
coup against the powerful regent
Sima Zhao, but he himself is killed before it comes to a confrontation. •
June 2 – Cao Mao is killed in a ''
coup d'état'' against Sima Zhao. The 14-year-old
Cao Huan becomes ruler of Former Wei, but the Sima clan controls the state.
By topic Art and Science • Earliest known date of
chess (approximate date).
Religion • Pope
Dionysius convenes a
synod at Rome to demand an explanation from bishop
Dionysius of Alexandria, who has been charged with separating the members of the
Trinity as three distinct deities. •
Paul of Samosata becomes
Patriarch of Antioch. == Births ==