Orthus lived with his master, Geryon, in a place called Erytheia, usually said to be somewhere in southern Spain.
Orthus was typically represented as a dog with two heads. Sometimes he had a snake for a tail.
Heracles killed Orthus during his tenth labor, while stealing the cattle of Orthus’ master, Geryon.
Orthus was a two-headed dog, one of the fearsome children of Echidna and Typhoeus. He served as a guard dog to Geryon, a monster with three heads and three bodies who lived somewhere at the edge of the world. When Heracles came to steal Geryon’s cattle for his tenth labor, both Orthus and his master were killed while trying to defend the herd.
The name “Orthus” (Greek Ὄρθος, translit. Órthos)1 may be etymologically connected to the Greek noun ὄρθρος (órthros), meaning “daybreak, dawn”—a word that may itself have Indo-European origins.2 The name also resembles another Greek word, ὀρθός (orthós), meaning “straight, upright.”
Ὄρθος (translit. Órthos), Ὄρθρος (translit. Órthros)
Orthus lived with his master (and cousin) Geryon in “sea-girt” Erytheia,3 a mysterious land at the edge of the world. Most ancient writers placed it somewhere in Spain, in the neighborhood of modern Cadiz.4
Orthus was typically said to have been a two-headed dog.5 But in artistic depictions (mostly on vase paintings), the number of heads varied between one and three. Sometimes he was also shown with a snake in place of a tail.6 In at least one tradition, Orthus was imagined as multiple guard dogs rather than a single multi-headed dog.7
One late source added that he had seven dragon or snake heads in addition to the canine ones.8
Orthus appeared only sporadically in ancient art, and only in connection with Heracles’ tenth labor (the theft of Geryon’s cattle). In those scenes, Orthus was usually shown lying dead, often with arrows protruding from his body.9
Orthus was one of the terrifying children of the monsters Typhoeus and Echidna.10 His siblings included Cerberus, the three-headed guard dog of the Underworld, who was captured by Heracles;11 the Hydra, a many-headed serpent, who, like Orthus, was slain by Heracles;12 and (possibly) the Chimera, a fire-breathing creature with the features of a goat, a lion, and a snake, who was killed by Bellerophon.13
According to Hesiod, Orthus mated with his sister Echidna (or his sister Chimera; the meaning of the passage is debated). Together they begot two additional monsters: the Sphinx (called “Phix” by Hesiod), who was defeated by Oedipus, and the Nemean Lion, whom Heracles strangled, skinned, and wore as armor.14
Orthus’ only mythological role was in connection with Heracles’ famous Twelve Labors. For the tenth labor, Heracles had been commanded by Eursytheus, his taskmaster, to travel to Erytheia and bring back the splendid cattle of Geryon.
When Heracles reached Erytheia, he first had to face Geryon’s guard dog, Orthus, and his herdsman, Eurytion. But this did not detain him long. According to Apollodorus, Heracles killed Orthus with a single swing of his heavy club. When Geryon’s herdsman came to help, Heracles swiftly dispatched him, too.
Geryon finally armed himself and came out to meet the hero who was hell-bent on stealing his cattle. But Heracles killed him just as quickly—either with his club or, according to Apollodorus, with a single arrow.15
The following is a selected list of important Greek and Roman sources on Orthus. Further sources and citations can be found in the notes above.
Hesiod (eighth/seventh century BCE): Orthus’ genealogy and mythology are summarized in the Theogony (287ff, 979ff).
Stesichorus (mid/late seventh century–ca. 550 BCE): Stesichorus’ Geryoneis, a long lyric poem, retells the myth of Heracles’ tenth labor and the deaths of Geryon and Orthus. It was very highly regarded in antiquity but now survives only in fragments.
Apollodorus (first century BCE/first few centuries CE): The Library, a mythological handbook incorrectly attributed to Apollodorus of Athens, contains a brief but important summary of the myth of Orthus and his connection with the tenth labor.
Antoni, Silke. “Orthus.” In Brill’s New Pauly, edited by Hubert Cancik, Helmuth Schneider, Christine F. Salazar, Manfred Landfester, and Francis G. Gentry. Published online 2006. http://dx.doi.org/10.1163/1574-9347_bnp_e901720.
Gantz, Timothy. “Labor X: The Cattle of Geryoneus.” In Early Greek Myth: A Guide to Literary and Artistic Sources, 402–8. Baltimore, MD: Johns Hopkins University Press, 1993.
Smith, William. “Heracles or Hercules.” In A Dictionary of Greek and Roman Biography and Mythology. London: Spottiswoode and Company, 1873. Perseus Digital Library. Accessed March 29, 2022. https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0104%3Aalphabetic+letter%3DH%3Aentry+group%3D7%3Aentry%3Dheracles-bio-1.
Stafford, Emma. “Geryon.” In Herakles, 42–45. New York: Routledge, 2012.
Theoi Project. “Orthros.” Published online 2000–2017. https://www.theoi.com/Ther/KuonOrthros.html.
Woodford, Susan. “Orthros I.” In Lexicon Iconographicum Mythologiae Classicae, vol. 7, 105–7. Zurich: Artemis, 1997.