Semo Sancus

In ancient Roman religion, Sancus (also known as Sangus or Semo Sancus) was a god of trust (fides), honesty, and oaths. His cult, one of the most ancient amongst the Romans, probably derived from Umbrian influences.

Sancus was also the god who protected oaths of marriage, hospitality, law, commerce, and contracts in particular. Some forms of swearings were used in his name and honour at the moment of the signing of contracts and other important civil acts. Some words (like "sanctity" and "sanction" - for the case of disrespect of pacts) have their etymology in the name of this god, whose name is connected with sancire "to hallow" (hence sanctus, "hallowed").

The temple dedicated to Sancus stood on the Quirinal Hill, under the name Semo Sancus Dius Fidius. Dionysius of Halicarnassus writes that the worship of Semo Sancus was imported into Rome at a very early time by the Sabines who occupied the Quirinal Hill. According to tradition his cult was said to have been introduced by the Sabines and perhaps king Titus Tatius dedicated a small shrine. The actual construction of the temple is generally ascribed to Lucius Tarquinius Superbus, although it was dedicated by Spurius Postumius on June 5 466 BC.

Sancus was considered the son of Jupiter, an opinion recorded by Varro and attributed to his teacher Aelius Stilo. He was the god of heavenly light, the avenger of dishonesty, the upholder of truth and good faith, the sanctifier of agreements. Hence his identification with Hercules, who was likewise the guardian of the sanctity of oaths. His festival day occurred on the nonae of June, i.e. June 5.

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