Gaul was named for its ancient inhabitants, the Gauls, a Celtic people. After all of Gaul was conquered by the Roman general Julius Caesar by 50 BCE, it became a central province of the Roman Empire. Gradually, the people assimilated into Roman culture, hence why modern historians refer to them as the “Gallo-Romans.” Even after the western half of the Roman Empire collapsed, the region continued to be called Gaul.

Geographically, Gaul’s boundaries were overall set by the Mediterranean Sea to the south, the Pyrenees Mountains to the southwest, the English Channel to the north, and the Rhine River and the Alps to the east. Its precise borders varied over time, but ancient and medieval Gaul generally encompassed what is today France, Luxembourg, Belgium, and parts of modern-day Switzerland, the Netherlands, northwestern Italy, and western Germany.

As Gregory of Tours details, Gaul was settled and conquered by the Franks, a migrating Germanic people. While the Gallo-Romans remained the majority population, the Franks became the ruling class of Gaul. The Gallo-Romans and the Franks co-existed for centuries with their own cultures, languages, and even law codes. Eventually, though, the two peoples merged into one culture.