TRIER (French Treves), an ancient city of Germany, for merly capital of an archbishopric and electorate of the empire, and now seat of a Roman Catholic bishop and chief town of a governmental department in the Prussian province of the Rhine. Pop. (1933) 76,652. It stands on the Moselle, about 6 m. from the Luxembourg frontier and 69 m. S.W. of Coblenz by rail on the Coblenz-Metz and Cologne-Saarbriicken lines.
Some of the piers and buttresses of the bridge over the Mo selle may date from about 28 B.C. The well-preserved amphi theatre just outside the modern town to the south-east was prob ably built in the reign of Trajan or Hadrian. It accommodated about 8,000 spectators. The most remarkable Roman building is the Porta Nigra, the fortified north gate of the city, 115 ft. long, 75 to 93 ft. high and 29 ft. deep, built of sandstone blocks and held together with iron clamps. This building may date from the 1st to the 4th century A.D. It is also called the Simeonstor, after a Greek hermit who inhabited it. In 1035 Archbishop Poppo converted the gate into two churches, one above the other, but all the additions except the apse have now been removed. In the south-east of the city are ruins of the Roman imperial palace, and near the bridge substructures of the 4th-century Roman baths, 66o ft. long. On the Constantinsplatz stands the brick basilica, probably of the age of Constantine. Converted into a palace for the Frankish kings and their deputies, it passed in '197 to the archbishops, and was restored (1846-56) and turned into a Protestant church.
Another Roman basilica forms the nucleus of the cathedral. Built under the emperors Valentinian I. and Gratian as a quadri lateral hall, it was converted into a church about the close of the 4th century, and restored by Bishop Nicetius about 55o. It is the most important pre-Carolingian church in Germany. Arch bishop Poppo and his successors in the nth and 12th centuries extended the cathedral and added an apse at each end. The vaulting of the nave and aisles and the cloisters were added in the 13th century. In the vaults are buried 26 archbishops and electors. The most famous relic preserved is the "Holy Coat of Trier," believed by the devout to be the seamless robe of the Saviour, and said to have been discovered and presented to the city by the empress Helena. The cloisters connect the cathedral with the church of Our Lady, a building in the form of a circle intersected by a cross, with a vault, built 1127-1143, and said to be the oldest Gothic church in Germany. St. Matthias in the
south, now represented by a 12th-century building, has a Chris tian cemetery of the Roman age. A market cross dates from 958, and a beautiful Renaissance fountain, the Petersbrunnen was erected in 1595. Close by are the Steipe or Rotes Haus, formerly the town hall, of the 15th century, and the Frankenturm or propugnacuhim, of the loth century.
The Provincial Museum (1885-89) contains many Roman and mediaeval antiquities, and the town library has valuable examples of early printing. Among its most treasured mss. are the codex aureus, a copy of the gospels presented to the abbey of St. Maxi min by Ada, a reputed sister of Charlemagne, and the codex Egberti of the loth century. At Igel is a remarkable Roman column, 83 ft. high. It dates from the 2nd century, and was the family monument of the Secundini. At Nennig is a fine Roman mosaic pavement.
The Treveri or Treviri, from whom the city derived its name, were one of the most powerful tribes among the Belgae, and ac cording to Julius Caesar, who conquered them in 56 B.C., pos sessed the best cavalry in Gaul. Attempts have been made to show that they were of German origin (see BELGAE), but al though they were doubtless subject to Germanic influences they spoke a Celtic language. The Roman city, Augusta Treverorum, was probably fortified by Augustus about 14 B.C., and organized as a colony about A.D. 50, in the reign of Claudius, but is not mentioned before the war of Civilis in 69 (Tacitus, Hist. iv.). At first the Treveri resisted the appeal of Civilis and his Batavi to join the revolt, and built a defensive wall from Trier to Ander nach, but soon after the two Treverans, Tutor and Classicus, led their fellow tribesmen, aided by the Lingones (Langres), in the attempt to set up a "Gallic emnire." After a brief struggle the rebels were overthrown at Trier by Cerealis, and 113 senators emigrated to Germany (7o). Mainly on account of its strategic position, Diocletian, on his reorganization of the empire, made Trier the capital not only of Belgica Prima, but of the whole "diocese" of Gaul. Constantine the Great, who generally resided here from 3o6 to 331, and his successors, beautified the city with public works, and villas arose upon the hillsides.