The Treveri were a Germanic or Celtic tribe of the Belgae group who inhabited the lower valley of the Moselle in modern day Germany from around 150 BCE, if not earlier, until their displacement by the Franks. Their domain lay within the southern fringes of the Silva Arduenna, a part of the vast Silva Carbonaria, in what are now Luxembourg, southeastern Belgium and western Germany; its centre was the city of Trier, to which the Treveri give their name. Celtic in language, according to Tacitus they claimed Germanic descent. They contained both Gallic and Germanic influences.

Gaulish is an extinct Celtic language spoken in parts of Continental Europe before and during the period of the Roman Empire. In the narrow sense, Gaulish was the language of the Celts of Gaul. In a wider sense, it also comprises varieties of Celtic that were spoken across much of central Europe ("Noric"), parts of the Balkans, and Anatolia ("Galatian"), which are thought to have been closely related. The more divergent Lepontic of Northern Italy has also sometimes been subsumed under Gaulish.