Year
400 BC was a year of the
pre-Julian Roman calendar. At the time, it was known as the
Year of the Tribunate of Esquilinus, Capitolinus, Vulso, Medullinus, Saccus and Vulscus (or, less frequently,
year 354 Ab urbe condita). The denomination 400 BC 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.