Parco Naturale del Fiume Sile

First information about Treviso can be found in the 3rd book of the Naturalis Historia by Pliny the Elder, where the «Fluvius Silis ex montibus Tarvisanis» is mentioned. Later, Venanzio Fortunato will mention the toponym «Tarvisus» for the first time, followed by the name «Trabision» mentioned by Anonimo Ravennate. Many references are also contained in the Historia Langobardorum by Paolo Diacono: «TribiciumseuTarbision», «apudTarvisium» etc.
The most likely hypothesis is that "Tarvisium", which can be broken up into Tarv-is-ium, is of celtic origin: it is possible indeed to identify the terms "tarvos", meaning bull, and the typical forming particle of the Gallic toponyms "-is-".