Ancient country, northeastern Gallia ( Gaul ).
One of the administrative areas into which Augustus divided Gaul, it stretched from the Seine River to the Rhine and included the Low Countries . Its capital was Durocortorum Remorum (now Reims ). Part of the area became Germania Inferior and Germania Superior under Domitian , and later, under Diocletian , the remainder was divided into Belgica Prima and Belgica Secunda. In the 5th century AD, Belgica was absorbed by the Franks . See also Belgium .