Trier (; , ; ; ; ; 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, Kempten, and Cologne).
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 southeast, and Koblenz, about northeast. The closest city to Trier is the capital of Luxembourg, some 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.
According to the legendarium recorded in the 12th-century Gesta Treverorum, the city was founded by an eponymous otherwise unrecorded Trebeta, an Assyrian prince, placing the city's founding legend centuries before and independently of ancient Rome: a medieval inscription on the façade of the Red House in Trier market,
"Thirteen hundred years before Rome, Trier stood / may it stand on and enjoy eternal peace, amen," reflects the proud city tradition. Further embroidery in the monkish Gesta made of Trebeta the son of Ninus, a "King of Assyria" imagined by the ancient Greeks, by a wife prior to his marriage to the equally non-historical Queen Semiramis. His stepmother, Semiramis, despised him and when she took over the kingdom after the death of his father, Ninus, Trebeta left Assyria and went to Europe. After wandering for a time, he led a group of colonizers to the site of Trier. Upon his death, his body was cremated on Petrisberg by the people of Trier. The image of "Trebeta" became an icon of the city during the Middle Ages.
In historical time, the Roman Empire subdued the Treveri in the 1st century BC and established Augusta Treverorum (Lit: August (Regal, noble) [City] of the Treveri) in 30 BC. The name is likely to be taken from the title Augustus held by the Princeps or head of state at the time, Augustus Caesar. The city later became the capital of the Roman province of Gallia Belgica, as well as the Roman prefecture of Gaul. It covered 282 ha within its walls and may have had as many as 70,000 inhabitants. The Porta Nigra is counted among the Roman architecture of the city. A residence of the Western Roman Emperor, Roman Trier was the birthplace of Saint Ambrose. Sometime between 395 and 418 the Roman administration moved the staff of Pretorian Prefecture from the city to Arles. The city continued to be inhabited, but was not as prosperous as before, because of the absence of 2,000 staff members of the Prefecture and military. However, the city remained the seat of a governor and had state factories for the production of ballistae and armor, and a wool mill for uniforms for the troops, clothing for the civil service and high-quality garments for the Court. Northern Gaul was held by the Romans along a line from north of Cologne to the coast at Boulogne through what is today southern Belgium until 460. South of this line, Roman control was firm, as evidenced by the continuing operation of the imperial arms factory at Amiens.
The Franks seized Trier from Roman administration in 459 AD. In 870, it became part of Eastern Francia, which developed into the Holy Roman Empire. Relics of Saint Matthias brought to the city initiated widespread pilgrimages. The bishops of the city grew increasingly powerful and the Archbishopric of Trier was recognized as an electorate of the empire, one of the most powerful states of Germany. The University of Trier was founded in the city in 1473.
In the 17th and 18th centuries, Trier was sought after by France, who invaded during the Thirty Years' War, the War of the Grand Alliance, the War of the Spanish Succession, and the War of the Polish Succession. France succeeded in finally claiming Trier in 1794 during the French Revolutionary Wars, and the electoral archbishopric was dissolved. After the Napoleonic Wars ended in 1815, Trier passed to the Kingdom of Prussia. Karl Marx was born in the city in 1818.
As part of the Prussian Rhineland, Trier developed economically during the 19th century. The city rose in revolt during the revolutions of 1848 in the German states, although the rebels were forced to concede. It became part of the German Empire in 1871.
In June 1940 over 60,000 British prisoners of war, captured at Dunkirk and Northern France, were marched to Trier, which became a staging post for British soldiers headed for German prisoner-of-war camps. Trier was heavily bombed and bombarded in 1944 during World War II. The city became part of the new state of Rhineland-Palatinate after the war. The university, dissolved in 1797, was restarted in the 1970s, while the Cathedral of Trier was reopened in 1974. Trier officially celebrated its 2,000th anniversary in 1984.