BELGICA. Or, Gallia Belgica.
Roman province, named after a Celtic tribe.
It was the northeastern province of Gaul, though it lost its frontier zones along the Rhine to form military districts facing Germany (the later provinces of Germania Superior and Inferior) and later lost its eastern lands in the later Franche-Comté and western Switzerland to Germania Superior.. The province was divided in the later Empire into Belgica Prima – the land between the Ardennnes and the Vosges (the upper Meuse and the valley of the Moselle except near its confluence with the Rhine) – and Belgica Secunda – the land of the Scheldte (Escaut), Somme and Aisne, of practically all the Oise, and of the upper Marne.
The name was sometimes used in the middle ages. In the modern era, the Walloon rebels against Austria in 1790 thought of calling the Austrian Netherlands Belgique; the Treaty of Vienna in 1815 used the term Belgic provinces to describe the old southern Netherlands; and the new state that broke away from the Kingdom of the Netherlands in 1830 took the name of Belgium.
The territories of Belgica Prima and Secunda became the ecclesiastical provinces of Trier and Reims respectively.