By most historical accounts, the Roman Emperor Caligula was a nightmareâa sadistic, debaucherous, and unstable despot. However, some new reevaluations of primary source documents and ethnobotanical fieldwork now suggests there was more to the madman than tyrannical bloodlust. According to a study published in the Proceedings of the European Academy of Sciences and Arts, Caligula was also fond of learning about medicinal plants.
Few ancient rulers are as infamous as Caligula. Ruling Rome from only 37 to 41 CE, historical accounts indicate that the young Roman Emperor managed to pack an impressive amount of cruelty, debauchery, and bizarre edicts into reign. Although initially depicted in a more positive light, sources like Suetoniusâ The Twelve Caesars describe Caligula as a âmonsterâ by the time of his assassination in 41 CE. Among his many misdeeds: the emperor wantonly ordered the torture and execution of enemies, engaged in multiple incestuous relationships, and declared himself a god. At one point, he even planned to appoint his horse as a consul.
An overlooked anecdote
However, Suetoniusâ biography of Caligula also includes an often overlooked anecdoteâone that caught the eye of experts at the Yale Ancient Pharmacology Program (YAPP). According to the 2nd century text, an unknown Roman senator who rose to the high rank of praetor once requested that Caligula grant him a leave of absence due to an undescribed ailment. The senator then traveled 65 miles northwest of Athens to the ancient Greek town of Antikyra to receive treatments concocted from âhellebore.â
Once there, he made the unwise choice: the senator asked Caligula to extend his stay. Instead, the Roman Emperor apparently ordered his execution, allegedly joking afterwards that, âa bloodletting was necessary for one whom hellebore had not benefited in all that time.â
But what is hellebore, and why the town of Antikyra? Furthermore, how did the doomed senator and Caligula already know about them? To find out, a team from YAPP decided to scour available historical texts as well as orchestrate a trip to the tiny town itself.

Ancient Romeâs Mayo Clinic
âIt is remarkable that Antikyra is mentioned in the historical record since it was never an important cultural or economic destination,â Trevor Luke, a YAPP faculty affiliate and Florida State University associate professor of classics as well as study co-author, said in a statement.
Luke and his colleagues found that while not a cultural or trading hub, the port town was known for medical concoctions based on a flowering plant called hellebore. These included treatments for, âmelancholy, insanity, epilepsy, and gout,â according to the study. Ancient texts also mention two types of helleboreâwhite hellebore for head issues, and black hellebore for the bowels.
âOur work suggests that Antikyra functioned as a kind of Mayo Clinic of the Roman worldâa place where affluent and influential Romans visited for medical treatments not widely available elsewhere,â explained Andrew Koh, YAPPâs principal investigator and research scientist at the Yale Peabody Museum.
There was a major problem. The âhelleboreâ growing today isnât necessarily the hellebore of ancient Rome. Todayâs botanical taxonomies didnât exist then, and plant identities often also shift over time and place. The studyâs authors cite an interview with an herbalist living in Antikyra today as an example: the individual knew âelleboroâ to be a dwarf elderberry, but the ancient text descriptions donât resemble the latter plant at all. Today, the closest area to host large amounts of âhelleboreâ matching its Roman description is about 25 miles north of Antikyraâover 2,500 feet above sea level on the southern slopes of Mount Helicon.
Regardless of the sourcing, Antikyraâs various hellebore potions were famous enough by the first century BCE for Roman âbigwigsâ like the senator to know of them, said Luke. He and his team also believe Caligula was well aware of the townâs speciality. After all, it promised potential cures for many of his own major issues, including epilepsy, insomnia, and âinsanity.â

Alternative treatments and theories
Trevor and Koh theorize that Caligula, already aware of Antikyra and how long a hellebore treatment should take, believed that the senator was abusing his leave of absence. Whatâs more, the âbloodlettingâ quip implies the emperor previously read De Medicina, a medical treatise written during the reign of Tiberius, Caligulaâs predecessor. In it, the author recommends bloodletting to epileptics as an alternative to hellebore.
âItâs [also] possible that Suetonius is wrong, and that Caligula wasnât ordering the manâs execution but simply prescribing an alternative treatment that he had read about or knew from his own experience,â said Luke.
Importantly, the team cautions that this is not meant to absolve Caligula of his many other atrocities. If anything, some of those accounts only further bolster the hypothesis that the emperor was well-versed in botany. He was a notorious fan of poisoning his enemies, for example, and the Hellenistic Jewish philosopher Philo described him as misusing the works of Apollo, god of medicine. Caligula was also convinced that his own father, Germanicus, died from poisoning, a belief that may have encouraged him to study medicinal plants in order to avoid the same fate.
Koh, Luke, and colleagues next plan to study the phytochemicals in hellebore specimens harvested from Greece, as well as test their biochemistry and efficacy against ancient medicineâs claims. In the meantime, they say their reevaluation isnât meant to clear Caligulaâs name, but instead offer a more complex look at the man.
âWeâre presenting a more complete and well-rounded version of Caligula as a ruler who was in tune with the medical wisdom of his day,â said Luke.