Trier, Germany, a city in the state of Rhineland-Palatinate. It is situated on the Mosel River, about 75 miles (120 km) south-southwest of Bonn. A major part of Trier's economy is trade in the fine wines produced in the area. Some of the most important Roman ruins in northern Europe are in Trier, including the Porta Nigra (a fortified city gate), an amphitheater, and public baths. In the cathedral at Trier are many religious relics, including a seamless robe said to have been worn by Jesus Christ.
A settlement existed at the site of Trier long before the first century B.C., when the Roman city of Augusta Treverorum was established. It was the capital of the province of Belgica, and later of a larger administrative district, the prefecture of Gaul. In the fifth century A.D. the city was abandoned to the invading Franks.
Early in the ninth century Trier became the seat of an archbishop. The archbishops of Trier were influential rulers with extensive land holdings. After 1356 they served as electors of the Holy Roman Empire (officials who helped choose the Holy Roman emperor). During the French Revolution France invaded the Archbishopric of Trier and, in 1801, secularized and annexed it. After the Congress of Vienna (1814–15), the territory passed to Prussia (which later became part of Germany). World War II bombing damaged or destroyed many of Trier's historic treasures.