Anna Perenna was an old Roman deity of the circle or "ring" of the year, as the name ("per annum") clearly indicates. Her festival fell on the Ides of March (March 15), which would have marked the first full moon in the year in the old lunar Roman calendar when March was reckoned as the first month of the year, and was held at the grove of the goddess at the first milestone on the Via Flaminia. It was much frequented by the city "plebs".