1911 Encyclopædia Britannica/Insubres
INSUBRES (Ἲσομβρες, Ἲνσουβροι), a Celtic people of upper Italy, the most powerful in Gallia Transpadana, inhabiting the country between the Adda, the Ticinus and the Alps. According to Livy (v. 34) they appear to have been a branch of the Aedui in Gallia Transalpina, though others assume that they were Umbrians, a view to some extent supported by the form Is-ombr-es. Livy states that Bellovesus and his Gauls, having crossed the Alps and defeated the Etruscans near the Ticinus, found themselves in the territory of the Insubres (also the name of a pagus of the Aedui). Here they built a city and called it Mediolanum (Milan), after the name of a village in their home in Gallia Transalpina. The name Insubres thus appears applied to the inhabitants (1) of the Aeduan pagus, (2) of the territory in Gallia Transpadana occupied by Bellovesus, (3) to the founders of Mediolanum. From 222 to 195 B.C. the Insubres were frequently at war with the Romans. In 222 they were defeated at Clastidium by M. Claudius Marcellus, who gained the spolia opima by slaying with his own hand their king Viridomarus (Virdumarus), and in 194 they were finally subdued by L. Valerius Flaccus.
See H. Nissen, Italische Landeskunde (1902) ii. 179; A. Holder, Altkeltischer Sprachschatz, ii. (1904).