Sister cities of Trier

Trier (German pronunciation: [ˈtʀiːɐ̯]; French: Trèves, IPA: [tʁɛv]; Luxembourgish: Tréier; Italian: Treviri; Latin: Augusta Treverorum; the Latin adjective associated with the city is Treverensis), historically called Treves in English, is a city in Germany on the banks of the Moselle. It may be the oldest city in Germany, founded in or before 16 BC (contested with Worms and Cologne).

Trier lies in a valley between low vine-covered hills of ruddy sandstone in the west of the state of Rhineland-Palatinate, near the border with Luxembourg and within the important Mosel wine region.

The city is the oldest seat of a Christian bishop north of the Alps. In the Middle Ages, the Archbishop of Trier was an important prince of the church, as the Archbishopric of Trier controlled land from the French border to the Rhine. The Archbishop also had great significance as one of the seven electors of the Holy Roman Empire.

With an approximate population of 105,000 Trier is ranked fourth among the state's largest cities; after Mainz, Ludwigshafen, and Koblenz. The nearest large cities in Germany are Saarbrücken, some 80 kilometres (50 miles) southeast, and Koblenz, about 100 km (62 mi) northeast. The closest city to Trier is the capital of Luxembourg, some 50 km (31 mi) to the southwest.

Trier is home to the University of Trier, the administration of the Trier-Saarburg district and the seat of the ADD (Aufsichts- und Dienstleistungsdirektion), which until 1999 was the borough authority of Trier, and the Academy of European Law (ERA). It is one of the five "central places" of the state of Rhineland-Palatinate. Along with Luxembourg, Metz and Saarbrücken, fellow constituent members of the QuattroPole union of cities, it also forms a central place of the greater region encompassing Saar-Lor-Lux (Saarland, Lorraine and Luxembourg), Rhineland-Palatinate, and Wallonia.