An oath (ὅρκος, iusiurandum, see preceding article) was a statement (assertory) or promise (promissory) strengthened by the invocation of a god as a witness and often with the addition of a *curse in case of perjury. A defendant in a lawsuit, for example, might swear by a god that his testimony was truthful and might specify the punishment for perjury. If the oath was false, the god, by effecting the provisions of the curse, would punish the individual, not for lying in court but for committing perjury. (See evidence, ancient attitudes to.) Throughout antiquity oaths were required of signatories to treaties, of parties to legal disputes, commercial and private contracts, conspiracies, and marriages, of governmental officials, judges, and jurors, and, particularly by the Romans, of soldiers (*sacramentum), and, under the empire, of citizens to affirm their allegiance to the emperor.Virtually any deity could be invoked as a witness, but in formal oaths the Greeks often called upon a triad of gods representing the sky, earth, and sea (*Helios or *Zeus, Ge (see gaia) or *Demeter, and *Poseidon); the Romans upon *Jupiter (Dius Fidius) and ‘all the gods’.