In the course of Julius Caesar's conquest of Gaul (58–51 BC), the Remi allied themselves with the Romans, and, by their fidelity throughout the various Gallic insurrections, secured the special favour of imperial power.

[1] At its height in Roman times the city had a population in the range of 30,000 – 50,000 or perhaps up to 100,000,[2] and was an important node in the road system of Gallia Belgica.

Mentions of Durocortorum from sources during Antiquity in chronological order are: Before the foundation of Durocorteron, the main settlement of the Remi was an oppidum located near the current villages of Variscourt and Condé-sur-Suippe close to Reims.

As shown by archeological finds in the necropolises found at the site, it was then succeeded by the oppidum of Durocortoron (latinised to Durocortorum) at the location of the city Reims.

[10] After Caesar's retreat, the armies of the Belgae attacked the Remi, but the Roman troops made a U-turn and came back to help their allies.

Durocortorum was therefore declared an allied city and allowed to be independent with the privilege of keeping its laws, religion, and government, and the Suessiones were put under their dominion.

It was delineated by four monumental gates, of which the Porte de Mars,[11] dedicated to the god of war, was oriented towards Gallia Belgica, which was in the process of pacification.

At the end of the 2nd century, the city was developing rapidly, benefiting from the progressively ensuing Pax Romana, which resulted in increased commerce.

The city also had its own supply of fresh water from an aqueduct (aqueduc de Reims) to the Suippe, a sewage system and a waste dump.

In 357 and 366 invasions of Germanic tribes are pushed back before they reach Metropolis Civitas Remorum (Reims) as Durocortorum is called during this period.

It seems the city was burned down and rebuilt several times, but little can still be found since the inhabitants, much poorer now, used cheap and easy to work but perishable materials such as wood, straw and clay.

They have revealed Roman houses, the gate of Mars, the sanctuary on the rue Belin, the forum, baths (thermae) and the necropolis at the exits of the city.