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. Cato and Silius Italicus wrote that Sancus was a Sabine god and father of the eponymous Sabine hero Sabus. He is thus sometimes considered a founder-deity.

His oaths were said to protect marriage, hospitality, law, commerce, and particularly formal contracts. Some of the oaths said at the moment of signing a contract (or other important civil promissory acts) named Sancus as guarantor, and called on him to protect and guard over the honour and integrity of the signatories' pledges.