In Greek mythology, Horkos (Ὅρκος) is the personification of an oath, and in particular the curse that falls upon anyone who swears falsely. He functions as a divine enforcer of oath-keeping, punishing perjury in the foreswearer and, in some accounts, in their descendants as well. Hesiod counts him among the many harmful figures born of Eris (Strife), while later authors associated his power with Zeus, the supreme guarantor of oaths.
Adapted from Wikipedia, "Horkos" · CC BY-SA 4.0
I.Family
In Hesiod's Theogony, Horkos is named as a son of Eris (Strife), born among her brood of injurious abstractions and with no father mentioned. Hesiod stresses that he is the greatest scourge to anyone on earth who knowingly swears a false oath, and that the Erinyes (Furies) attended his birth, an apt detail since both they and Horkos punish perjury.
A divergent tradition appears in the tragedian Sophocles, who calls Horkos a son of Zeus. This made mythological sense, since Zeus Horkios ("Zeus of Oaths") was regarded as the supreme guarantor of sworn agreements.
II.Role and mythology
Horkos embodies the conditional self-curse that a person calls down upon themselves when swearing an oath; the curse is realized when the oath is broken. In Hesiod's Works and Days he runs alongside Justice (Dike) to punish those who give crooked judgments and forswear themselves. Hesiod also notes that the fifth days of the month are dreadful, for it was on the fifth that the Erinyes were said to attend upon the birth of Oath, whom Eris bore as a bane to perjurers.
According to Herodotus, Horkos has a nameless son, a figure without hands or feet, who nonetheless pursues the oath-breaker swiftly and relentlessly, destroying the perjurer's entire family and line. This image expresses the belief that the consequences of a broken oath could reach across generations.
III.Cult
A fearsome cult image of Zeus Horkios stood at Olympia, where competitors in the Olympic Games swore oaths to compete honestly. The traveler Pausanias records that the statue, holding thunderbolts in each hand, was deliberately fashioned to strike terror into would-be cheats, reinforcing the sanctity of the oaths sworn before it.