Year 360 (CCCLX) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Iulianus (or, less often, year 1113 Ab urbe condita). The number 360 for this year has been used since the early Middle Ages, when the Anno Domini calendar era became the main method in Europe for naming years.
|Centuries:||3rd century – 4th century – 5th century|
|Decades:||330s 340s 350s – 360s – 370s 380s 390s|
|Years:||357 358 359 – 360 – 361 362 363|
- February – Julian, Roman Caesar, is proclaimed emperor by the Gallic legions in Lutetia (modern Paris) at the Thermes de Cluny. They refuse to support the eastern campaign against king Shapur II of Persia and revolted.
- The Alamanni raid Raetia (Switzerland), but are pushed back behind the Rhine and into the Black Forest by Julian.
- King Shapur II continues his campaign against the Roman fortresses. His armies capture Singara, Bezabde and Nisibis.
- Emperor Constantius II and Julian send several letters to each other. They are both hoping to avoid a civil war.
- Thousands of Huns invade Europe. They spread terror as they take over territories held for generations by Alans, Heruls, Ostrogoths and Visigoths.
- Roman authorities in Britain export wheat to supply the legions on the Rhine. They have encouraged production of wheat for that purpose.
- First Council of Constantinople: Emperor Constantius II requested a church council, at Constantinople, and both the eastern and western bishops attend the meeting. Wulfila also attends the council and endorses the resulting creed. After the council, several homoiousian bishops are deposed or banished, including Macedonius I of Constantinople and Cyril of Jerusalem.