Trier in Rhineland-Palatinate, whose history dates to the Roman Empire, is the oldest city in Germany. Traditionally it was known in English by its French name of Treves.
Prehistory
The first traces of human settlement in the area of the city show evidence of linear pottery settlements dating from the early Neolithic period. Since the last pre-Christian centuries, members of the Celtic tribe of the Treveri settled in the area of today's Trier.See: Heinen, pp. 1-12.
Roman Empire
The Romans under Julius Caesar first subdued the Treveri in 58 to 50 BC. No later than 16 BC, at the foot of the hill later christened the Petrisberg, upon which a military camp had been set up in 30 BC and abandoned again a few months later, the Romans founded the city of ("City of Augustus in the land of the Treveri"),See: Heinen, pp. 30-55. which has a claim to being the oldest city in Germany.Paul Stephenson, Constantine, Roman Emperor, Christian Victor 2010: :"Trier" 124ff. The honour of being named after the Emperor was only locally shared by Augsburg and Augst in northern Switzerland. Following the reorganisation of the Roman provinces in Germany in 16 BC, Emperor Augustus decided that the city should become the capital of the province of Belgica. Shortly before AD 100, an amphitheatre was built, the signal sign of a city of any importance. By the first half of the second century another major structure, a Roman circus, had reached truly monumental proportions.
Trier rose in importance during the Empire's third-century crisis, as the chief city of the province of Gallia Belgica. From 271 to 274 AD, Trier was the second city of the breakaway Gallic Empire, at first under Postumus, who was proclaimed in Cologne, then under his ephemeral successor, Victorinus, who made his base at Trier, where he had rebuilt a large house with a mosaic proclaiming his position as tribune in Postumus' Gallic Praetorian Guard;Stephenson 2010:124. the city served again as capital under the emperors Tetricus I and II. From the second half of the 3rd century onwards, Trier was the seat of an archbishopric; the first bishop being Eucharius.See: Heinen, pp. 327-347. In the year 275, the city was destroyed in an invasion by the Alamanni. Diocletian recognized the urgency of maintaining an imperial presence in the Gauls, and established first Maximian, then Constantius Chlorus as caesars at Trier; from 293 to 395, Trier was one of the residences of the Western Roman Emperor,See: Heinen, pp. 211-265. and its position required the monumental settings that betokened imperial government.
A mint was immediately established by Constantius, which came to be the principal mint of the Roman West. A new stadium was added to the amphitheater, to stage chariot races. Under the rule of Constantine the Great (306–337), the city was rebuilt and buildings such as the PalastaulaSee: Kuhnen, pp. 135-142. (known today as the Constantine Basilica) and the Imperial Baths (Kaiserthermen), the largest surviving Roman baths outside Rome, were begun under Constantius and completed c 314,A coin of 314 was found in a construction trench (Stephenson 2010:125). constructedSee: Dehio, p. 1031. by his son Constantine, who left Trier in the hands of his son Crispus. In 326, sections of the imperial family's private residential palaces were extended and converted to a large double basilica, the remains of which are still partly recognisable in the area of the Trier Cathedral (Trierer Dom) and the church "Liebfrauenkirche".See: Kuhnen, pp. 114-121. See also: Dehio, pp. 1033-1051. A demolished imperial palace has left shattered sections of painted ceiling, which scholars believe once belonged to Constantine's young wife, Fausta, whom he later put to death.Preserved in Trier's Diocesan Museum; Stephenson 2010:125 and fig. 25.
From 318 onwards Trier was the seat of the Gallic prefecture (the Praefectus Praetorio Galliarium) which governed the western Roman provinces from Morocco to Britain. The praetorian prefects usually numbering 3–4, were the senior civilian officials taking precedence over all other officials and army officers. They were vice-regents of the emperors who alone with them could pronounce final verdicts. Constantine's son Constantius II resided here from 328 to 340. Roman Trier was the birthplace of Saint Ambrose ca. 340, who later became the Bishop of Milan and was eventually named a Doctor of the Roman Catholic Church long after his death in 397. It is also where Saint Athanasius was first exiled by Constantine in 336.
From 367 under Valentinian I Trier once more became an imperial residence until 375. It was the largest city north of the Alps. Gratian resided there for most of his reign until assassinated in 383. It was the capital of Magnus Maximus, who ruled the prefecture of Gaul, as emperor from 383 to 388. Valentinian II visited the city. In 407, shortly after the invasion of Gaul by the Vandals, Alans and Suebi, the Gallic prefecture was relocated to Arles, on the Rhône.
Roman Trier had been subjected to attacks by Germanic tribes from 350 onwards, but these had been repulsed by Emperor Julian. After the invasions of 407 the Romans were able to reestablish the Rhine frontier and hold northern Gaul tenuously until the end of the 450s, when control was finally lost to the Franks and local military commanders who claimed to represent central Roman authority. During the early 5th century, sources indicate Trier was sacked four times by the Franks. According to Lanting & van der Plicht (2010), this happened in 411 (more probable than 407), 413, 421, and probably 428 or 435. The Huns under Attila also sacked Trier in 451. The city became definitively part of Frankish territory (Francia Rhinensis) around 485; the last Roman administrator of Trier was Arbogast. As a result of the conflicts of this period, Trier's population decreased from an estimated 80,000 in the 4th century to 5,000 at the beginning of the 6th century.See: Heinen, pp. 366-384.
Middle Ages
By the end of the 5th century, Trier was under Frankish rule, first controlled by the Merovingian dynasty, then by the Carolingians. The city still maintained a small group of romance speaking inhabitants in the early 8th century.Romance speakers in Mosella valley & Trier; p.14 (in Italian) As a result of the Treaty of Verdun in 843, by which the grandsons of Charlemagne divided his empire into three parts, Trier was incorporated into the Kingdom of Lorraine (Lotharingia). After the death of Lothair II, ruler of Lorraine, Trier in 870 became part of the East Frankish Empire, later called Germany, under Henry I.See: Anton / Haverkamp, pp. 22-67.
Many abbeys and monasteries were founded in the early Frankish time, including St. Maximin, St. Martin, St. Irminen, St. Maria ad Martyres/St.Mergen and others.See: Dehio, pp. 1054-1057. The only important abbey that survived wars and secularization by the French at the beginning of 1800 is the Benedictine abbey St. Matthias in the south of Trier. Here, the first three bishops of Trier, Eucharius, Valerius and Maternus are buried alongside the apostle Saint Matthias.See: Dehio, pp. 1057-1063. This is the only tomb of an apostle to be located in Europe north of the Alps, thus making Trier together with Rome in Italy (burial place of St. Peter the apostle) and Santiago de Compostela in Spain (tomb of St. James) one of three major places of pilgrimage in Europe for Catholics. In 882, Trier was sacked by the Vikings, the Great Danish Army, who burnt most churches and abbeys. This was the end of the systematically built Roman Trier.See: Petzold, pp. 36-39.
Medieval legend, recorded in 1105 in the Gesta Treverorum, makes Trebeta son of Ninus the founder of Trier.See: Petzold, p. 82. Also of medieval date is the inscription at the facade of the Red House of Trier market, ANTE ROMAM TREVIRIS STETIT ANNIS MILLE TRECENTIS. PERSTET ET ÆTERNA PACE FRVATVR. AMEN. ("Thirteen hundred years before Rome, Trier stood / may it stand on and enjoy eternal peace, amen.") being mentioned in the Codex Udalrici of 1125.
From 902, when power passed into the hands of the archbishops, Trier was administered by the Vogt of the archbishopric, which developed its own seal in 1149. The Archbishop of Trier was, as chancellor of Burgundy, one of the seven Electors of the Holy Roman Empire, a right which originated in the 12th or 13th century, and which continued until the French Revolution. From the 10th century and throughout the Middle Ages, Trier made several attempts to achieve autonomy from the Archbishopric of Trier, but was ultimately unsuccessful. In 1212, the city received a charter from Emperor Otto IV, which was confirmed by Conrad IV. In 1309, however, it was forced to once again recognise the authority of the Archbishop, who was at that time the imposing Baldwin of Luxembourg, son of the Count of Luxemburg.See: Anton / Haverkamp, pp. 239-293.
Elected in 1307 when he was only 22 years old, Baldwin was the most important Archbishop and Prince-Elector of Trier in the Middle Ages. He was the brother of the German King and Emperor Henry VII and his grandnephew Charles would later become German King and Emperor as Charles IV. He used his family connections to add considerable territories to the Electorate of Trier and is also known to have built many castles in the region. When he died in 1354, Trier was a prospering city.See: Anton / Haverkamp, pp. 295-315.
The status of Trier as an archbishopric city was confirmed in 1364 by Emperor Charles IV and by the Reichskammergericht; the city's dream of self-rule came definitively to an end in 1583. Until the demise of the old empire, Trier remained the capital of the electoral Archbishopric of Trier, although not the residence of its head of state, the Prince-Elector. At its head was a court of lay assessors, which was expanded in 1443 by Archbishop Jacob I to include bipartisan mayors.See: Anton / Haverkamp, pp. 570-579.
The Dombering (curtain wall of the cathedral) having been secured at the end of the 10th century, Archbishop Theoderich I and his successor Arnold II later set about surrounding the city by walls.See: Petzold, p. 43. This curtain wall, which followed the path now taken by the Alleenring, enclosed 1.38 square kilometres.
Modern age
In 1473, Emperor Frederick III and Charles the Bold, Duke of Burgundy convened in Trier. In this same year, the University of Trier was founded in the city.See: Anton / Haverkamp, pp. 531-552.
From 1581 until 1593, intense witch persecutions, involving nobility as well as commoners, abounded throughout this region, leading to mass executions of hundreds of people.
In the 17th century, the Archbishops and Prince-Electors of Trier relocated their residences to Philippsburg Castle in Ehrenbreitstein, near Koblenz. A session of the Reichstag was held in Trier in 1512, during which the demarcation of the Imperial Circles was definitively established.
The Thirty Years' War (1618–1648) did initially not touch Trier. Warfare reached the city as part of the French–Habsburg rivalry and the conflict between townspeople and the archbishop Philipp Christoph von Sötern. The city asked the Spanish government in Luxemburg for help against the bishop's absolutist tendencies in 1630. While Spain sent troops and installed a garrison, the bishop used the aid of French troops to regain Trier two times in 1632 and 1645, interrupted by a surprise Spanish attack in 1635 and 10 years of Spanish occupation and imprisonment of the bishop, an event that served as a pretext to start the Franco-Spanish War. The cathedral chapter finally disempowered the bishop in 1649 using mercenaries and Lorrain troops against the bishop's French auxiliary forces.