a town of the Ubii, in Gallia Belgica, mid-way between the rivers Rhine and Roer; now called Balchusen. BELGICA Gallia, one of the three divisions of Gaul men- Belgium, bounded by the ocean on the north, the rivers Seine and Marne on the west, and the Rhine on the east. The southern boundary differed at different times. Augustus added to Gallia Belgica the Sequani and Helvetii, who till then had formed part of Celtic Gaul. The Belgae are described by Caesar as the bravest of the Gauls, because untainted by the importation of foreign luxuries.