Year 231 (CCXXXI) was a common 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 Claudius and Sallustus (or, less frequently, year 984 Ab urbe condita). The denomination 231 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.

The NSN length is 7, 8 or 9 digits, depending on the number type.

Year 231 (CCXXXI) was a common 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 Claudius and Sallustus (or, less frequently, year 984 Ab urbe condita). The denomination 231 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.

The NSN length is 7, 8 or 9 digits, depending on the number type.