Trier, formerly known in English as Treves and Triers, is a city in Germany on the banks of the Moselle. Trier 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, it was later conquered by the Romans in the late-1st century BC and renamed Trevorum or Augusta Treverorum. Trier may be the oldest city in Germany. 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, as the archbishop-electorate controlled land from the French border to the Rhine. The Archbishop-Elector 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.