Ancient Roman Holiday Dedicated to the God of Mildew

This 3rd-century CE mosaic illustrates the month of April in the Ancient Roman world, which was then, as now, a time when sun and rains could be expected as part of the spring season. It was during this month that the religious feast devoted to the deity of mildew was celebrated.

The Ancient Romans worshipped many Gods and Goddesses outside of the famous pantheon, and Robigus — usually considered male but on occasion female — was one of them. April 25 was “Robigalia,” the holiday dedicated to this divine personification of agricultural disease.

What one wanted from Robigus was for the deity to go away. Romans propitiated Robigus on the holiday with a ceremony in which a type of priest called the Quirinus, dedicated to the God of war, would walk outside the city boundaries to a point where Rome turned into agricultural fields, and there sacrifice a dog in order to keep Robigus from spoiling the new spring crops with mildew. Rust fungi were common fungal parasites that covered plants with red blotches, and there is a connection with the color red (which forms the root word “Rob-” as in Robigalia), blood, and warfare.

The first-century poet Ovid linked the holiday overtly with war and destruction in his _Fasti_ a long poem outlining Roman holy days. He describes the Quirinus priest’s prayers to Robigus:

“Scaley mildew, spare the blades of corn (ie, grain)/ And let their tender tips quiver above the soil . . . Wind and showers don’t harm the wheat as much,/ Nor gleaming frost that bleaches the yellow corn,/ As when the sun heats the moist stalks:/ Then, dreadful goddess, is the time of your wrath. . . Grip harsh iron rather than tender wheat,/ Destroy whatever can destroy others first./ Better to gnaw at swords and harmful spears . . . Let rust stain weapons:/ And whoever tries to draw his sword from its sheath,/ let him feel it wedded there by long disuse.”