Trier, formerly known in English as Trèves and Triers, is a city on the banks of the Moselle in Germany. It lies in a valley between low vine-covered hills of red sandstone in the west of the state of Rhineland-Palatinate, near the border with Luxembourg and within the important Moselle wine region.
Founded by the Celts in the late 4th century BC as Treuorum and conquered 300 years later by the Romans, who renamed it Augusta Treverorum, Trier is considered Germany's oldest city. It is also the oldest seat of a bishop north of the Alps. In the Middle Ages, the archbishop-elector of Trier was an important prince of the Church who controlled land from the French border to the Rhine. The archbishop-elector of Trier also had great significance as one of the seven electors of the Holy Roman Empire.
With an approximate population of 105,000, Trier is the fourth-largest city in its state, after Mainz, Ludwigshafen, and Koblenz. The nearest major cities are Luxembourg, Saarbrücken, and Koblenz.