Wikipedia
The Belgae ( or ) were a large confederation of tribes living in northern Gaul, between the English Channel, the west bank of the Rhine, and northern bank of the river Seine, from at least the third century BC. They were discussed in depth by Julius Caesar in his account of his wars in Gaul. Some peoples in Britain were also called Belgae and O'Rahilly equated them with the Fir Bolg in Ireland. The Belgae gave their name to the Roman province of Gallia Belgica and, much later, to the modern country of Belgium.
Usage examples of "belgae".
Belgae were on their knees, but one more campaign would see a permanent cessation to Belgic resistance.
Real knowledge begins with two Celtic invasions, that of the Goidels in the later part of the Bronze Age, and that of the Brythons and Belgae in the Iron Age.
And I very much doubt that the Belgae will want them any more than the Celtiberians of the Pyrenees.
King of Demetia, had come with a party of his dreaded Blackshields, while Lancelot, King of the Belgae, was escorted by a dozen giant men of his Saxon Guard and by the baleful pairs of twins, Dinas and Lavaine and Amhar and Loholt.
So strong and populous was the city that the Trinobantes, during the years that had elapsed since the Romans took possession of it, remained passive under the yoke of their oppressors, and watched, without attempting to take part in them, the rising of the Iceni and Brigantes, the long and desperate war of the Silures and Ordovices under Caractacus, and the reduction of the Belgae and Dumnonii from Hampshire to Cornwall by Vespasian.
We certainly did not come thence, for all our traditions say that the Iceni came by ship from a land lying due east from us, and that we were an offshoot of the Belgae, whose country lay to the northwest of Gaul.
One part is inhabited by the Belgae, another by the Aquitani, and the third by those who are called Celts in their own language, and Gauls in ours.
Before Britain lost her freedom, the country was irregularly divided between thirty tribes of barbarians, of whom the most considerable were the Belgae in the West, the Brigantes in the North, the Silures in South Wales, and the Iceni in Norfolk and Suffolk.
The Remi said, that they had known accurately every thing respecting their number, because being united to them by neighborhood and by alliances, they had learned what number each state had in the general council of the Belgae promised for that war.
After he perceived that all the forces of the Belgae, which had been collected in one place, were approaching toward him, and learned from the scouts whom he had sent out, and [also] from the Remi, that they were then not far distant, he hastened to lead his army over the Aisne, which is on the borders of the Remi, and there pitched his camp.
He charges him to visit the Remi and the other Belgians, and to keep them in their allegiance and repel the Germans (who were said to have been summoned by the Belgae to their aid,) if they attempted to cross the river by force in their ships.