Has Ergot Altered Events in World History?

Has Ergot Altered Events in World History?

Ergot is a small-grain disease caused by the fungal pathogen, Claviceps purpurea. The word “ergot” is derived from the French word “argot,” meaning “spur.” The term can also refer to the sclerotia, structures resembling a rooster’s spur, that form within grain heads after infection and displace the developing seed. These dark brown to black structures are simply masses of fungal hyphal tissues containing the toxic chemicals that can cause disease (ergotism) in animals if ingested.

This is one of the few plant diseases that can also cause direct damage to humans. Ergotism is characterized by a host of symptoms, depending on the specific chemicals involved. Some of the more common symptoms include tremors, delusions, prickling sensations on skin, convulsing seizures, hallucinations, and violent muscle spasms.

The plant disease is favored by severely cold winters followed by a cool, wet growing season, and historically has occurred more commonly in areas highly dependent on rye for sustenance. Although all cereal crops are vulnerable, rye is more susceptible than other cereals due to flowers being open-pollinated and staying open longer, thus remaining exposed for longer periods of time.

Ergot Epidemics Date Back to Middle Ages and Likely Before

Ergot has been known for millennia, but was not recognized as causing health issues until about 200 years ago. For example, an Assyrian tablet dating to 600 BC mentions “noxious pustules” on grain seeds.

Documented epidemics of ergotism occurred frequently in the Middle Ages (500-1500), now known to be caused by eating ergot-contaminated rye bread, resulting in the deaths of tens of thousands of people. It was most common in those colder, damp areas of Europe that were highly dependent on rye as a food source. This region extended through central and eastern Europe — the chief rye-growing areas. It was rare in the United Kingdom, where rye is not consumed as much and the climate is less favorable for ergot development.

In an earlier Panhandle Perspectives column I wrote about the supposition of ergot’s role in the causation and conduction of witchcraft trials throughout Europe and colonial America. However, this disease has also been attributed to influencing other events in world history.

The French Revolution

One of the events leading to the French Revolution was referred to as the “The Great Fear.” This event was characterized by a general panic by the population, resulting in mob mentality, violence, and riots from July 17 to Aug. 3, 1789.

Grain yields were very poor that year with widespread shortages expected, and rumors swept through villages that bandits were about to seize what was left of the year's grain harvest. In response to the rumors, fearful peasants throughout the rural provinces mobilized, took up arms, and attacked and looted their overlords’ manors.

The reason for this spontaneous mass hysteria remains a puzzle to today. Historian Mary K. Matossian argued that one of the causes of the Great Fear was consumption of grain contaminated with the ergot fungus. In years of good harvests, grain contaminated with ergot was discarded, but when the harvest was poor, there was little other option for food. Thus, a severe ergot epidemic may have affected the mental state of French peasants, thereby contributing to the French revolution in 1789.

Demographic Depression (1750-1850)

Matossian also contended that ergot food poisoning enhanced by climate and dietary changes also played a role in population depression in certain countries, for example rye-consuming France compared to wheat-eating England. Fertility and mortality records showed steady growth in England with more erratic and gradual growth in France.

Records also provide strong evidence that fertility suppression was greater in France during this period with decreased birth rates and increased infant mortality. As the British became less dependent upon rye, they conceived more children while suffering fewer infant deaths during the summer months of July to September.

Furthermore, during the first half of 19th century, the summers in England were not warm enough for adequate ergot development, while in warmer France, conditions were better for ergot development. Thus it is now postulated that both fortunate weather conditions and a dietary preference toward wheat over rye allowed higher growth rates in England by reducing ergotism.

Effects on War

It is possible that ergot may also be responsible for Russia’s lack of a warm-weather seaport.

In 1772, the Russian Tsar Peter the Great tried to capture several water ports on the Black Sea from Turkey. His soldiers were stopped at Astrakhan (a city in southern Russia located on the Volga River delta where it empties into the Caspian Sea) due to an ergot epidemic.

They obtained hay for their horses and bread for themselves derived from ergot-infected rye. Both man and beast were affected, destroying their ability to battle the Turks. They were forced to retreat.


Carefoot, G.L. and Sprott, E.R. 1967. Famine on the wind. Man’s battle against plant disease. Rand McNally and Company, 231 pp. van Dongen, P. W. J., and de Groot, Akosua, N. J. A. 1995. History of ergot alkaloids from ergotism to ergometrine. Europ. J. Obstetrics and Gynecology 60: 109-116.

Lee, M. R. 2009. The history of ergot of rye (Claviceps purpurea) I: from antiquity to 1900. J. Royal College Physicians of Edinburgh 39: 179-184.

Matossian, M. K. 1989. Poisons of the past: molds, epidemics, and history. Yale University Press, New Haven Conn., 190 pp.

Tippo, O., and Stern, W. L. 1977. Humanistic botany. W. W. Norton and Company, New York, 605 pp.

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