Store Banner Desktop

Store Banner Mobile

Cacus – The One Who Dared Cross Hercules

Cacus – The One Who Dared Cross Hercules

Getting your Trinity Audio player ready...

According to Roman mythology, Cacus was a thief who stole from the hero Hercules (whose Greek equivalent was Heracles), which was the action that resulted in the former’s death. There are several versions of this myth, as it has been recounted by different authors.

Although not considered to be amongst the most famous Roman myths, the story of Cacus and Hercules is significant for a number of reasons. For the ancient Romans, the story served as an etiology for the cult of Hercules at the Ara Maxima. The myth may also be read as an allegory of the gradual replacement of local Italic cultures (as symbolized by Cacus) by a Hellenistic one (represented by Hercules).

Cacus the Evil

The name ‘Cacus’ is said to be derived from ancient Greek, and means ‘bad’ or ‘evil’. Indeed, in all versions of the myth, Cacus plays the role of the antagonist. In some, however, he is presented as a monstrous creature. This is seen, for example, in Virgil’s Aeneid. In the Book 8 of this epic poem, Virgil has the story of Cacus and Hercules told to Aeneas by Evander, who founded the city of Pallantium on the future site of Rome, prior to the Trojan War.

Evander describes Cacus as a “foul-featured, half-human monster” who lived in “a cave which the rays of the Sun never reached.” The cave of Cacus is believed to be situated on the Aventine Hill. Evader also informs Aeneas that Cacus was the son of Vulcan (the Roman counterpart of the Greek god Hephaestus), and that “it was his father’s black fire he vomited from his mouth as he moved his massive bulk.”

Cacus was not only a monster in form, but also in behavior. Evander states that the floor of Cacus’ cave was “always warm with freshly shed blood,” whilst “the heads of men were nailed to his proud doors and hung there pale and rotting.” Therefore, the people of the area prayed to the gods to end Caucus’ reign of terror. Their prayers were eventually answered with the arrival of Hercules, who, at that point of time, had just accomplished one of his famous Twelve Labors.

Front panel frieze from a sarcophagus with the Labors of Hercules. (Museo nazionale romano di palazzo Altemps / Public domain)

Front panel frieze from a sarcophagus with the Labors of Hercules. (Museo nazionale romano di palazzo Altemps / Public domain)

These were a series of impossible tasks that the hero had to perform as penance. Hercules had killed his wife, Megara, and their children in a fit of madness sent by Hera, and was thus forced to become a servant of Eurystheus (one Hercules’ cousins, and the king of Tiryns) for twelve years. It was Eurystheus who came up with the Twelve Labors, and imposed them on Hercules.     

The Tenth Labor: Slaying of the Giant

The myth of Cacus and Hercules is associated with the Tenth Labor, which is the acquisition of the cattle of Geryon. In order to complete this task, Hercules had to travel to island of Erythia (meaning ‘red’), which is said to be located in the westernmost part of the world, near the boundary of Europe and Libya. On the island was a herd of cattle whose coats were stained red by the rays of the setting Sun. The cattle, however, belonged to a terrifying giant called Geryon.

According to the myths, Geryon was the son of Chrysaor and Callirrhoe. The former was a man who had sprung from the body of the Gorgon Medusa when she was decapitated by Perseus, whilst the latter was the daughter of Oceanus and Tethys. The physical description of Geryon varies according to the source.

Heracles fighting Geryon, amphora by the E Group, c.540 BC. (Louvre Museum / Public domain)

Heracles fighting Geryon, amphora by the E Group, c.540 BC. (Louvre Museum / Public domain)

In some, for instance, he is described as a giant with three heads attached to one body, whilst others state that he had three bodies. In some versions, Geryon is even said to have wings. In addition to Geryon, the cattle were guarded by herdsmen, one of whom, Eurytion, was slain by Hercules, as well as a two-headed dog called Orthus (the brother of Cerberus).

Having slain Eurytion, Orthus, and Geryon, Hercules faced no further opposition on the island, and was therefore able to begin his journey back to Tiryns with the cattle. This journey home turned out to be more troublesome than the initial theft of the cattle. Interestingly, the encounter with Cacus on the Aventine Hill in Rome was only one of the many troubles faced by Hercules as he brought the cattle before Eurystheus.

Hercules driving off the cattle of Geryon, at the right are the nymphs of Hesperides. (Giulio Bonasone (c.1531) / Public domain)

Hercules driving off the cattle of Geryon, at the right are the nymphs of Hesperides. (Giulio Bonasone (c.1531) / Public domain)

For example, in Liguria (in northwest Italy), two of Poseidon’s sons tried to steal the cattle, so Hercules killed them. In another instance, one of the cattle broke loose, and swam to the island of Sicily from Rhegium (in southern Sicily), before wandering off to a neighboring country. Apparently, the native word for ‘bull’ was ‘italus’, and hence the whole country became known as Italy.

Finally, as Hercules arrived at the edge of the Ionian Sea, and was on the verge of completing his labor, Hera sent a gadfly to attack the cattle, causing the herd to scatter far and wide. As a consequence, Hercules was forced to wander around Thrace in search of the missing cattle, before he could return home.

Theft From Under the Nose of Hercules

The story of Hercules’ journey from Erythia back to Tiryns with the cattle of Geryon shows that the hero travelled along the length of the Italian Peninsula. Therefore, it would not have been difficult for the Cacus episode to be inserted into this myth. According to Evander, when the herd was grazing in the valley, and drinking from the river, Cacus “stole from the pasture four magnificent bulls and as many lovely heifers”, and brought the animals to his cave.

Cacus, however, knew that Hercules would come looking for the stolen cattle. Therefore, in order to prevent any hoofprints from pointing to his cave, thereby revealing the location of the cattle, he “dragged them in by their tails to reverse the tracks”.

In the meantime, the remaining cattle had finished grazing, and Hercules was moving them out of the pasture, and prepared to continue on his journey. It was at this moment that Cacus’ theft of the cattle was revealed, “the cows began to low plaintively at leaving the place, filling the whole grove with their complaints, and bellowing to the hills they were leaving behind them. Then, deep in the cave, a single cow lowed in reply. Cacus had guarded her well, but she thwarted his hopes.”

Hercules and Cacus by Baccio Bandinelli (1525–34), Piazza della Signoria, Florence, Italy. (VarnakovR / Adobe stock)

Hercules and Cacus by Baccio Bandinelli (1525–34), Piazza della Signoria, Florence, Italy. (VarnakovR / Adobe stock)

Hercules’ Wrath Was Felt

The furious Hercules went after Cacus, who fled in terror back to his cave, and shut its entrance by jamming the doorposts with a huge rock. This proved to be a challenge, even for the mighty Hercules, “there was Hercules in a passion, trying every approach, turning his head this way and that and grinding his teeth. Three times he went around the whole of Mount Aventine in his anger. Three times he tried to force the great rock doorway without success. Three times he sat down exhausted in the valley.”

Having failed to move the stone from the entrance, Hercules climbed to the top of the cave, and unroofed it. There was no escape for Cacus, and a battle was fought between him and Hercules, “so Cacus was caught in the sudden rush of light and trapped in his cavern in the rock, howling as never before, while Hercules bombarded him from above with any missile that came to hand, belaboring him with branches of trees and rocks the size of millstones.

There was no escape for him now, but he vomited thick smoke from his monstrous throat and rolled clouds of it all round his den to blot it from sight. Deep in his cave he churned out fumes as black as night and the darkness was shot through with fire. Hercules was all past patience. He threw himself straight down, leaping through the flames where the smoke spouted thickest and the black cloud boiled in the vast cavern. There, as Cacus vainly belched his fire in the darkness, Hercules caught him in a grip and held him, forcing his eyes out of their sockets and squeezing his throat till the blood was dry in it.

Engraving of Hercules killing Cacus at his cave, from The Labors of Hercules. (Hans Sebald Beham (c.1525) / Public domain)

Engraving of Hercules killing Cacus at his cave, from The Labors of Hercules. (Hans Sebald Beham (c.1525) / Public domain

After slaying Cacus, Hercules opened the cave, and brought his cattle out. He also dragged the corpse out into the open for all to see. The death of Cacus was celebrated by the local population, who honored Hercules as a hero from then onwards, “ever since that time we have honored his name and succeeding generations have celebrated this day with rejoicing. This altar was set up in its grove by Potitius, the first founder of these rites of Hercules, and by the Pinarii, the guardians of the rites. We shall always call it the greatest altar, and the greatest altar it will always be.”

Varying Accounts: Just an Ordinary Shepperd?

The myth of Cacus and Hercules is found not only in Virgil’s Aeneid, but also in other Roman sources, such as Ovid’s Fasti, and Livy’s History of Rome. It may be mentioned, however, that there is no evidence for the existence of this myth prior to the Augustan period. Thus, it has been suggested that the myth may have been a recent invention, although it deals with the earliest history of Rome.

Interestingly, elements of Greek mythology can be detected in the story. For instance, the theft of Hercules’ cattle bears similarities to the theft of Apollo’s cattle by Hermes. It has also been argued that the myth may have been inspired by an obscure myth, in which Sisyphus steals the Mares of Diomedes (Hercules’ Eighth Labor). The comparison with Hermes and Sisyphus casts Cacus in a different light, i.e. as a cunning rogue, rather than a brutish monster.     

Hermes and Apollo with the cattle in the background. (Francesco Albani / Public domain)

Hermes and Apollo with the cattle in the background. (Francesco Albani / Public domain)

Although Virgil paints Cacus as a terrifying monster, this is not always the case with the other Roman writers. In Livy’s account, for example, Cacus is said to be a local shepherd who desired Hercules’ cattle, and therefore committed the theft.

Livy also explains how this ordinary shepherd was able to steal from the great hero, “he [Hercules] swam across the Tiber, driving the oxen before him, and wearied with his journey, lay down in a grassy place near the river to rest himself and the oxen, who enjoyed the rich pasture. When sleep had overtaken him, as he was heavy with food and wine, a shepherd living near, called Cacus, presuming on his strength, and captivated by the beauty of the oxen, determined to secure them.”

Like Virgil’s Cacus, Livy’s shepherd also drags the cattle into his cave by their tails, thereby concealing their tracks. Likewise, it was the lowing of the animals from inside the cave that revealed their hidden location. As a consequence, Hercules went to the cave, and Cacus was killed as he tried to stop the hero from entering it, “as Cacus tried to prevent him by force from entering the cave, he was killed by a blow from Hercules’ club, after vainly appealing for help to his comrades.”

Hercules beating Cacus with his club with the cattle behind him. (Marten Ryckaert / Public domain)

Hercules beating Cacus with his club with the cattle behind him. (Marten Ryckaert / Public domain)

The story continues with the establishment of Hercules’ cult. This time, however, the hero is honored not because he vanquished a monster, but because of a prophecy. Evander, whom Livy claimed was the king at that time, was the son of a prophetess by the name of Carmenta, who prophesized that Hercules would one day become a god.

Therefore, after meeting Hercules, Evander decided to build a shrine for him, an offer which the hero accepted, “Hercules grasped Evander's right hand and said that he took the omen to himself and would fulfil the prophecy by building and consecrating the altar. Then a heifer of conspicuous beauty was taken from the herd, and the first sacrifice was offered; the Potitii and Pinarii, the two principal families in those parts, were invited by Hercules to assist in the sacrifice and at the feast which followed.” 

The Myth’s Legacy        

Although the myth of Cacus and Hercules is not very well-known in modern times, it was an important one for the ancient Romans. This myth served as the foundation story of the Ara Maxima, the oldest cult center of Hercules in Rome. Although the monument is no longer in existence, it is believed that it once stood in the eastern part of the Forum Boarium (ancient Rome’s cattle market), not far from the so-called Temple of Hercules Victor.

The myth may also be interpreted as an allegory, in which the local Italic cultures, which were considered to be less advanced, were replaced by the more sophisticated culture of the Greeks. Alternatively, it may be argued that the story was meant to depict the Romans as the rightful successors of the Greek civilization.

Top image: Hercules standing over Cacus beating him with his club.        Source: Hendrick Goltzius, (1588) / Public domain

By Wu Mingren


Atsma, A. J., 2017. Geryon. [Online]
Available at:

Atsma, A. J., 2017. Kakos. [Online]
Available at:

Encyclopedia Mythica, 1997. Cacus. [Online]
Available at:

Livy, History of Rome [Online]

[Roberts, W. M. (trans.), 1905. Livy’s History of Rome.]

Available at:

Platner, S. B., 1929. Ara Maxima Herculis. [Online]
Available at:

Sutton, D., 1977. The Greek Origins of the Cacus Myth. The Classical Quarterly, 27(2), pp. 391-393.

The Editors of Encyclopaedia Britannica, 2011. Cacus and Caca. [Online]
Available at:

The Editors of Encyclopaedia Britannica, 2020. Heracles. [Online]
Available at:

Virgil, Aeneid

[West, D. (trans.), 2003. Virgil’s Aeneid, London: Penguin Books.], 2020. Geryon. [Online]
Available at:, 2020. The Cattle of Geryon. [Online]
Available at:, 2020. The Hercules and Cacus Myth. [Online]
Available at:



Hera sending a gadfly after the cow as she did with Io makes me wonder if Romans associated the insect with the goddess

dhwty's picture


Wu Mingren (‘Dhwty’) has a Bachelor of Arts in Ancient History and Archaeology. Although his primary interest is in the ancient civilizations of the Near East, he is also interested in other geographical regions, as well as other time periods.... Read More

Next article