The Belgae were a group of tribes living in northern Gaul, between the English channel and the west bank of the Rhine, from at least the 3rd century BC. They were later found also in Britain, and possibly even Ireland. The Belgae gave their name to the Roman province of Gallia Belgica, and very much later, to the modern country of Belgium.
Read more about Belgae: Etymology, Origins of The Belgae, Tribes of The Belgae, Conquest of The Belgae, Belgae Outside Gaul