This isolation formed in itself a powerful and perfect barrier between the inhabitants of the plain and those of the high grounds.  The first held firm to their primitive customs and their ancient language; the second finished by speaking Latin, and borrowing all the manners and usages of Italy.  The moral effect of this contrast was that the people, once so famous for their bravery, lost, with their liberty, their energy and their courage.  One of the Batavian chieftains, named Civilis, formed an exception to this degeneracy, and, about the year 70 of our era, bravely took up arms for the expulsion of the Romans.  He effected prodigies of valor and perseverance, and boldly met and defeated the enemy both by land and sea.  Reverses followed his first success, and he finally concluded an honorable treaty, by which his countrymen once more became the allies of Rome.  But after this expiring effort of valor, the Batavians, even though chosen from all nations for the bodyguards of the Roman emperors, became rapidly degenerate; and when Tacitus wrote, ninety years after Christ, they were already looked on as less brave than the Frisons and the other peoples beyond the Rhine.  A century and a half later saw them confounded with the Gauls; and the barbarian conquerors said that “they were not a nation, but merely a prey.”

Reduced into a Roman province, the southern portion of the Netherlands was at this period called Belgic Gaul; and the name of Belgium, preserved to our days, has until lately been applied to distinguish that part of the country situated to the south of the Rhine and the Meuse, or nearly that which formed the Austrian Netherlands.

During the establishment of the Roman power in the north of Europe, observation was not much excited toward the rapid effects of this degeneracy, compared with the fast-growing vigor of the people of the low lands.  The fact of the Frisons having, on one occasion, near the year 47 of our era, beaten a whole army of Romans, had confirmed their character for intrepidity.  But the long stagnation produced in these remote countries by the colossal weight of the empire was broken, about the year 250, by an irruption of Germans or Salian Franks, who, passing the Rhine and the Meuse, established themselves in the vicinity of the Menapians, near Antwerp, Breda and Bois-le-duc.  All the nations that had been subjugated by the Roman power appear to have taken arms on this occasion and opposed the intruders.  But the Menapians united themselves with these newcomers, and aided them to meet the shock of the imperial armies.  Carausius, originally a Menapian pilot, but promoted to the command of a Roman fleet, made common cause with his fellow-citizens, and proclaimed himself emperor of Great Britain, where the naval superiority of the Menapians left him no fear of a competitor.  In recompense of the assistance given him by the Franks, he crossed the sea again from his new empire, to aid them in their war with the Batavians, the allies of Rome; and having seized on their islands, and massacred nearly the whole of its inhabitants, he there established his faithful friends the Salians.  Constantius and his son Constantine the Great vainly strove, even after the death of the brave Carausius, to regain possession of the country; but they were forced to leave the new inhabitants in quiet possession of their conquest.