257

Year 257 (CCLVII) was a common year starting on Thursday of the Julian calendar. At the time, it was known as the Year of the Consulship of Valerianus and Gallienus (or, less frequently, year 1010 Ab urbe condita). The denomination 257 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.