Gods of oaths

Gods of oaths preside over oaths and promises.

Greek Mythology

 * Helios: a Greek Titan and guardian of oaths.
 * Horkos: the Greek spirit of oaths.

Roman Mythology

 * Dius Fidius: the Roman god of oaths.
 * Orcus: a Roman god who punishes those who break oaths.
 * Sancus: a Roman god of oaths.