Carausius was from which province, today a part of Belgium and Luxembourg?
Carausius:  He was a Menapian from Belgic Gaul, who usurped power in 286, during the Carausian Revolt, declaring himself emperor in Britain and northern Gaul (Imperium Britanniarum). Gallia Belgica: Gallia Belgica ("Belgic Gaul") was a province of the Roman empire located in the north-eastern part of Roman Gaul, in what is today primarily Belgium, Luxembourg and the Netherlands.
Gallia Belgica