Gnaeus Julius Agricola, Roman general (d. 93)
AD 40 (XL) was a leap year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Augustus without colleague (or, less frequently, year 793 Ab urbe condita). The denomination AD 40 for this year has been used since the Early Middle Ages, when the Anno Domini calendar era became the prevalent method in Europe for naming years.