History of Robigalia

Hello Robigalia Reader, welcome to a special edition of the Robigalia Newsletter.

Today marks the anniversary of Robigalia, the ancient Roman festival dedicated to protecting crops against disease. It also commemorates one year of the Robigalia newsletter. To celebrate this milestone, I'm excited to present a special edition of the newsletter, a historical tribute to the festival that inspired its name.

A year ago, I had the harebrained idea of starting a plant pathology newsletter during the final stretch of my PhD. What began as a weekly communication on plant pathogens to a small circle of readers has since evolved into a global community of plant pathologists that continues to grow. Admittedly, running the newsletter on my own isn’t always easy, but watching it grow has been an immense source of joy.

Perhaps my favourite segment of the newsletter has been the Research Student of the Week segment. This has given me the chance to learn about the amazing research being undertaken by students, ranging from biocontrol agents, effector targets, improving disease management, and host production of defensive chemicals.

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Now, let’s get into it…

Robigalia according to Ovid

The Roman poet Ovid played a crucial role in documenting the Robigalia festival through his poetic work, the Fasti. In Book IV of this calendar poem, which details Roman religious festivals month by month, Ovid provides the most extensive surviving literary account of Robigalia. He describes not only the rituals, such as the procession of participants dressed in white to a sacred grove at the city’s boundary, and the sacrifice of a red-coated puppy and a sheep, but also includes the actual prayer recited to the deity Robigus or Robigo, asking for protection of the crops from disease.

Other sources provide only brief mentions of Robigalia, leaving Ovid’s Fasti as the primary literary source for our understanding of the festival’s rituals, religious significance, and cultural context. Ovid’s narrative is written as an eyewitness account, with him claiming to have encountered the priest and the procession by chance and joined in to observe the ceremony. He also recorded his conversation with the priest, in which he inquires about the reasons for the dog sacrifice, preserving explanations and interpretations that might otherwise have been lost.

The beginning of Robigalia

The Robigalia festival was generally attributed to Rome’s second king, Numa Pompilius, who is said to have established it during the eleventh year of his reign, around 700 B.C. Belonging to a series of agricultural festivals celebrated in April, the festival coincided with the critical growth phase of wheat, when plants are most susceptible to rust and other diseases. Other festivals during this time included the Cerealia (dedicated to Ceres), the Fordicidia, the Parilia, and the Vinalia.

Despite their technological and organisational sophistication, the Romans remained acutely aware of their vulnerability to crop diseases and failures. While these spring festivals collectively served to celebrate and vitalise the growing season, they also reflected deep anxieties about potential crop failures, leading to a dependence on divine intervention to prevent losses.

The deity: Robigus or Robigo

Central to the Robigalia festival was its deity, Robigus (masculine) or Robigo (feminine), who was understood as the personification of agricultural disease—specifically the wheat rust that could devastate grain crops. The deity was believed to be a divine presence or spirit (numen) of agricultural disease, capable of both causing and preventing it. The Romans did not view such entities as evil in the modern sense, but rather as powerful forces that required proper ritual attention to ensure they acted beneficently rather than harmfully.

Ritual components and celebration

The Robigalia festival combined several distinctive ritual elements that together formed a complex religious observance aimed at securing divine protection for vulnerable crops. For an agrarian society like Rome, where food security depended primarily on grain production, the threat of wheat rust represented a genuine existential concern, one that demanded supernatural intervention.

Sacred location and procession

The festival took place at the boundary of Rome's territory (Ager Romanus), specifically at a sacred grove located at the fifth milestone along the Via Claudia. This location at Rome's edge was symbolically significant, as it positioned the ritual at the border between cultivated and uncultivated lands.

The festivities began with a procession from the city to this sacred grove, with participants dressed in white garments, creating a visually striking scene as they moved through the countryside. Ovid, in his Fasti, describes personally encountering this procession by chance and joining it to witness the rituals firsthand.

Sacrificial practices

The central and most distinctive ritual of the Robigalia was the sacrifice of a dog, specifically, an unweaned puppy and a sheep. The dog chosen for sacrifice typically had red fur, believed to symbolically represent the reddish-brown colour of wheat rust itself. This sacrifice was performed by the Flamen Quirinalis, the high priest of the god Quirinus. Observations of the festival by Ovid note that the priest would wear the entrails of the animals before throwing them into a ritual fire along with incense, wine, and the animal’s blood.

The use of a dog as a sacrificial animal wasn’t commonplace in ancient Rome, appearing as a public sacrifice in only a few instances, including the Robigalia and Lupercalia festivals. Most animal sacrifice in ancient Rome resulted in a communal meal, involving domestic animals whose flesh was a normal part of the Roman diet. Dogs were rarely sacrificed in official state ceremonies, appearing more commonly in magical practices and private rites dedicated to chthonic (underworld) deities. Some ancient sources, including Ovid, suggested that the sacrifice was intended to appease the Dog Star (Sirius), whose rising was associated with scorching heat and crop disease.

Prayers and invocations

Along with performing the sacrificial acts, the Flamen Quirinalis would offer specific prayers asking Robigus/Robigo to spare the crops from blight. One prayer recorded by Ovid pleaded:

The Robigalia festival was just one example of the many prayers and rituals Romans used to protect their crops. Prayers to major deities such as Ceres (goddess of grain), Tellus (Earth), and Mars (protector of fields) were common in both public festivals and private rituals.

Games and races

Unsurprisingly, watching a dog sacrifice was not always a major drawcard for the public. To increase participation in the festival and enhance enjoyment of what was otherwise a solemn affair, the Robigalia included games (ludi) in the form of chariot races. These races had two divisions: younger participants drove two-horse chariots (biga), while more experienced racers used four-horse chariots (quadriga). The races were dedicated to both Mars and Robigo, further cementing the connection between agricultural protection and Roman martial deities.

Christian adaptation

Robigalia’s legacy extended well beyond the fall of ancient Rome. In the Christian era, the festival was transformed into the Rogation Days, with Pope Gregory I instituting a major Rogation on 25 April to replace the pagan observance. The Christian version featured processions and prayers for the protection of crops, but dispensed with animal sacrifice, maintaining the agricultural focus within a new religious context.

Robigalia today

Thankfully, modern-day plant pathology no longer calls for a sacrificial dog or prayer (although, working with non-model plants, I have been known to plead with my plants to grow faster). Instead of appealing to a higher power to protect our crops, we develop tools to rapidly detect, diagnose, treat, and prevent plant disease.

Through the Robigalia newsletter, I hope not only to create a global community of plant pathologists, but also to increase awareness of the crucial role plant pathology plays in today’s changing world.

I hope you’ve enjoyed this special edition of the newsletter.

Until next time,

Alyssa