SANGUS, or SEMO SANCUS, a Roman divinity, is said to have been originally a Sabine god, and identical with Hercules and Dius Fidius. (Lactant. 1.15; Ov. Fast. 6.216; Propert. 4.9,74; Sil. Ital. 8.421.) The name which is etymologically the same as Sanctus, and connected with Sancire, seems to justify this belief, and characterises Sancus as a divinity presiding over oaths. Sancus also had a temple at Rome, on the Quirinal, opposite that of Quirinus, and close by the gate which derived from him the name of Sanqualis porta. This sanctuary was the same as that of Dius Fidius, which had been consecrated in the year B. C. 465 by Sp. Postumius, but was said to have been founded by Tarquinius Superbus (Liv. 8.20, 32.1; Dionys. A. R. 9.60; Ov. Fast. 6.213, &c.), and the ancients thoroughly identified their Dius Fidius with Sancus. He is accordingly regarded as the protector of the marriage oath, of the law of nations, and the law of hospitality. (Dionys. A. R. 4.58 ; Varro, De Ling. Lat. 5.66.) Sancus is said to have been the father of the Sabine hero Sabus. (Dionys. A. R. 2.49; August. de Civ. Dei, 18.19 ; Lactant. l.c.)
[L.S]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890