The term "Belgae" refers to a group of ancient tribes that inhabited the region known as Gallia Belgica, which corresponds to parts of modern-day Belgium, France, and Luxembourg. They were known for their fierce resistance against Roman expansion and played a significant role in the conflicts during the late Roman Republic. The Belgae were described by the Roman general Julius Caesar in his work, "Commentarii de Bello Gallico." He noted that they were distinct from other Gallic tribes due to their unique customs and warrior culture. The Belgae ultimately faced defeat in the Gallic Wars, leading to Roman control over their territory.