Gaul Ancient Roman name for the land n of the Pyrenees, s and w of the Rhine and w of the Alps. In 900 bc, tribes of Celts began to migrate across the Rhine and spread s. In 222 bc, the Romans conquered the region s of the Alps, calling it Cisalpine Gaul. By 121 bc, Rome captured the area n of the Alps, known as Transalpine Gaul. In the Gallic Wars (58–51 bc), Caesar completed the conquest of Gaul.

Gaul an ancient region of Europe, corresponding to modern France, Belgium, the south Netherlands, SW Germany, and northern Italy. The area south of the Alps was conquered in 222 bc by the Romans, who called it Cisalpine Gaul. The area north of the Alps, known as Transalpine Gaul, was taken by Julius Caesar between 58 and 51 bc; the southern province of Transalpine Gaul became known as Gallia Narbonensis.