|Centuries:||2nd century – 3rd century – 4th century|
|Decades:||230s 240s 250s – 260s – 270s 280s 290s|
|Years:||257 258 259 – 260 – 261 262 263|
|260 by topic|
|State leaders – Sovereign states|
|Birth and death categories|
|Births – Deaths|
|Establishment and disestablishment categories|
|Establishments – Disestablishments|
|Ab urbe condita||1013|
|Chinese calendar||己卯年 (Earth Rabbit)
2956 or 2896
— to —
庚辰年 (Metal Dragon)
2957 or 2897
|Coptic calendar||−24 – −23|
|- Vikram Samvat||316–317|
|- Shaka Samvat||181–182|
|- Kali Yuga||3360–3361|
|Iranian calendar||362 BP – 361 BP|
|Islamic calendar||373 BH – 372 BH|
|Minguo calendar||1652 before ROC
|Seleucid era||571/572 AG|
|Thai solar calendar||802–803|
Year 260 (CCLX) was a leap year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Saecularis and Donatus (or, less frequently, year 1013 Ab urbe condita). The denomination 260 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.
- Battle of Edessa: With a large army, said to number 70,000 men, Valerianus attempts to drive the Persians back from Edessa. The Roman army is surrounded and most of its troops are killed or captured. Valerianus is taken prisoner for the remainder of his life.
- 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).
- Persian king Shapur I destroys Caesarea Mazaca in Asia Minor.
- Cao Huan succeeds Cao Mao as ruler of the Chinese Kingdom of Wei.
- Syria, Egypt and Palestine break off from the Roman Empire to form the Persian-supported Palmyrene Empire.
Arts and sciences
- Earliest known date of chess.
- 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.
- Cao Mao, ruler of the Chinese Kingdom of Wei (killed in an abortive coup d'état against Sima Zhao) (b. 241)
- Chen Tai, minister of the Kingdom of Wei
- Empress Cao, daughter of Cao Cao and wife of Emperor Xian of Han (b. 197)
- Saloninus, Roman emperor and son of Gallienus (b.242)
- Sun Liang, Emperor of the Chinese Kingdom of Wu (b. 243)
- Valerianus I, Roman emperor (approximate date)