In pre-Roman Gaul

Gaul

Gaul was a region of Western Europe during the Iron Age and Roman era, encompassing present day France, Luxembourg and Belgium, most of Switzerland, the western part of Northern Italy, as well as the parts of the Netherlands and Germany on the left bank of the Rhine. The Gauls were the speakers of...

 the Gaulish tribe

Gauls

The Gauls were a Celtic people living in Gaul, the region roughly corresponding to what is now France, Belgium, Switzerland and Northern Italy, from the Iron Age through the Roman period. They mostly spoke the Continental Celtic language called Gaulish....

 of Veliocasses or Velocasses controlled a large area in the lower Seine valley

Seine

The Seine is a -long river and an important commercial waterway within the Paris Basin in the north of France. It rises at Saint-Seine near Dijon in northeastern France in the Langres plateau, flowing through Paris and into the English Channel at Le Havre . It is navigable by ocean-going vessels...

, which retains a trace of their name, as the Vexin

Vexin

The Vexin is a historical county of northwestern France. It covers a verdant plateau on the right bank of the Seine comprising an area east-to-west between Pontoise and Romilly-sur-Andelle , and north-to-south between Auneuil and the Seine near Vernon...

. According to Julius Caesar

Julius Caesar

Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....

' Commentary on the Gallic Wars the Veliocasses participated in the tribal coalition of Belgae

Belgae

The Belgae were a group of tribes living in northern Gaul, on the west bank of the Rhine, in the 3rd century BC, and later also in Britain, and possibly even Ireland...

 that resisted the Romans in 57 BCE. In 52 they raised 3000 men to support Vercingetorix

Vercingetorix

Vercingetorix was the chieftain of the Arverni tribe, who united the Gauls in an ultimately unsuccessful revolt against Roman forces during the last phase of Julius Caesar's Gallic Wars....

, and fought alongside the Bellovaci

Bellovaci

The Bellovaci were among the most powerful and numerous of the Belgic tribes of north-eastern Gaul conquered by Julius Caesar in 57 BC. The name survives today in the French city of Beauvais, called by the Romans Caesaromagus.- Geography :...

 in the final rebellion against Roman hegemony.
Pliny

Pliny the Elder

Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

 mentions the Vellocasses in his Naturalis Historia (4.18), and Ptolemy

Ptolemy

Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

 (2.8 §8) the Oueneliokasioi.

In the time of Augustus

Augustus

Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...

 they were included in Gallia Lugdunensis

Gallia Lugdunensis

Gallia Lugdunensis was a province of the Roman Empire in what is now the modern country of France, part of the Celtic territory of Gaul. It is named after its capital Lugdunum , possibly Roman Europe's major city west of Italy, and a major imperial mint...

. Their capital was Rotomagus (Rouen

Rouen

Rouen , in northern France on the River Seine, is the capital of the Haute-Normandie region and the historic capital city of Normandy. Once one of the largest and most prosperous cities of medieval Europe , it was the seat of the Exchequer of Normandy in the Middle Ages...

).