Once subdued, Belgium accepted the Roman rule and remained loyal to the Empire. Civilization was rapidly introduced; great military roads were constructed through the Belgian forests and marshes, connecting the different towns, and along their course villages were built and farms developed. Tongres and Tournai became entirely Romanized cities, where splendid monuments were built; remains of these are still to be found today. Farms were laid out and country houses were erected according to Roman pattern, with such changes as were imposed by the rigors of the northern climate. The Belgians adopted Roman manners and customs and the Latin language: they became Gallo-Romans, and even the national gods were renamed with Roman names. If Belgium shared the splendor and the civilization of the Roman Empire, it shared also the disastrous days of its decline. There came a time when the Empire, once so strong, but now growing weaker and weaker, was quite unable to resist the hordes of barbarians, which, coming from the dark forests of Germany, threatened the rich provinces of Gaul, and Italy itself, with invasion. From the third century on, Franks and Alamans devastated Gaul and left the wealthy territories covered with ruins. The emperors did not succeed in expelling the Franks from the country: those tribes of Teutonic race were allowed to remain in the northern parts of Belgium, Flanders and Campine,[4] and became soldiers of the Empire. They early became dissatisfied with the territory allotted to them and resumed their march southward, conquering the whole of Belgium. The year 406 witnessed a terrible catastrophe. The Teutons, driven out of their country by the invasion of the Huns, burst like a hurricane upon the unfortunate provinces of Belgium, burned and devastated everything on their march, destroyed Tongres and Tournai, and finally, swarming over the Alps and the Pyrennees, invaded both Italy and Spain. After their passage, Belgium was left undefended by the Roman legions, recalled to defend Italy itself, and the Franks of Flanders and Campine occupied the abandoned territory without difficulty.