A Roman goddess of growth, identical to Ceres. She was honored during the festival of the Ambarvalia in May; a rural festival for the purification (lustratio) of the country, and for invoking the blessing of Ceres upon the fruits of the earth.
Dea Dia's grove was at the Vigna Ceccarelli, a little beyond the fifth milestone on the Via Portuensis. Her priests were the fratres Arvales. The presiding officer, or magister, was elected annually in her grove on the second or great day of the May festival, but not coming into office until the 17th of December.
- Smith, William. (1870). Dictionary of Greek and Roman Biography and Mythology. London: Taylor, Walton, and Maberly.