To what race shall we attribute the foundation of the city of Carcassonne? We cannot say exactly, so many races having occupied this part of the valley of the Aude in turn; the first in point of time was that of the Iberians, that mysterious people, who had colonized Southern Europe long before the coming of the Aryan race. Without taking any more account than is necessary regarding the hypothesis of the etymologists, we may recall the fact that the celebrated William von Humboldt attaches the vocable _Carcaso_, as well as many others from the south of Gaul and the north of Spain, to the Iberic language. Erected into a Latin colony by Cæsar himself, or by his adopted son, Augustus, Carcassonne vegetated obscurely for three centuries until the day when the invasion by the Barbarians and the civil wars brought about the ruin of the Empire. At this moment she was shorn of her ancient glory; and from a Latin colony, she became a simple _castrum_, which many manuscripts of the _Notitia dignitatum_, written about the year 400, do not even mention. But if the old city lost her importance with regard to civil life, she gained it in military life. At the moment the Germans, those hereditary enemies of Rome, spread over the whole of Gaul, the cities repaired their too long neglected fortifications in great haste; open spaces they surrounded with high walls; the ancient citadels were reinforced; and in their haste, just as happened later during the Hundred Years’ War, many sumptuous buildings erected by Latin architects, were sacrificed to make the defences. Carcassonne is now furnished with a strong enclosure, the honour of which many archæologists, among them Viollet-le-Duc, wish to give to the Visigoths; but it seems more prudent to attribute them to the last engineers of the expiring Empire. This enclosure, of which some parts still exist to-day, is composed of curtains of medium height, surmounted by a parapet without projections and flanked at intervals with semicircular towers opened at the gorge, or closed by a flat wall. The towers were bare up to the level of the circling road, higher they comprised two or three stories. Viollet-le-Duc supposes that they were covered with a roof, and restored one according to this hypothesis. Much more elevated than the curtain, these Gallo-Roman towers commanded it from above, and on each of their flanks the curtain is interrupted by a gap connected by a narrow bridge, which was easy to destroy in case of an attack.