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.