Gauls
In 58 BC Julius Caesar launched the Gallic Wars and had conquered the whole of Gaul by 51 BC. He noted that the Gauls (Celtae) were one of the three primary peoples in the area, along with the Aquitanians and the Belgae. Caesar's motivation for the invasion seems to have been his need for gold to pay off his debts and for a successful military expedition to boost his political career. The people of Gaul could provide him with both. So much gold was looted from Gaul that after the war the price of gold fell by as much as 20%. While they were militarily just as brave as the Romans, the internal division between the Gallic tribes guaranteed an easy victory for Caesar, and Vercingetorix's attempt to unite the Gauls against Roman invasion came too late. After the annexation of Gaul a mixed Gallo-Roman culture began to emerge.
Battle of Alesia
Alesia proved to be the end of generalized and organized resistance against Caesar's invasion of Gaul and effectively marked the end of the Gallic Wars. In the next year (50 BC) there were mopping-up operations. During the Roman civil wars Gallia was essentially left on its own. Marcus Vipsanius Agrippa became its first governor in 39–38 BC. In 39 BC he settled the Ubians on the west bank of the River Rhine and in 38 BC he suppressed a rebellion in Aquitania. He built a radial network of roads centred on the Gallic capital, Lugdunum (Lyon). Gallia was divided into three Roman provinces; Gallia Aquitania, Gallia Lugdununensis and Gallia Belgica. Only the Arverni kept their independence thanks to their victory against Caesar at the Battle of Gergovia.