Trier Capital of the North
the Emperor Augustus decided that the city should
become the capital of the province of Belgica.

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 Augusta Treverorum "City of Augustus in the land of the Trever"

after the Diocletian Reforms, it became the capital of the prefecture of the Gauls, overseeing much of the Western Roman Empire. In the 4th century, Trier was one of the five biggest cities in the known world with a population around 75,000 and perhaps as much as 100,000 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 in Late Antiquity Under the rule of Constantine the Great (306–337), the city was rebuilt with many fine buildings. From 367, under Valentinian I, Trier once more became an imperial residence (lasting until the death of Theodosius I in 395 AD) and remained the largest city north of the Alps. It was for a few years (383 – 388) the capital of Magnus Maximus, who ruled most of the western Empire.




The city began to surpass Rome itself in importance and was equal in power with Milan, Sirmium, and Nicomedia.
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 Constantine Basilica
and the Imperial Baths, the largest surviving Roman baths outside Rome,
were begun under Constantius and completed c 314 constructed. by his son Constantine.