Shortly after the departure of the Romans the German immigrants seem to have completely overpowered the original Belgæ, and, like true Aryans, to have divided themselves into a number of separate and independent municipalities, with no established capital and acknowledging no central authority. At times these communities did submit themselves to the rule of Dukes and Counts, but only to a very limited extent; and for particular purposes they occasionally even sought the protection of some powerful monarch; but they never relinquished their right of self-government nor fell under the power of feudal chiefs, or of a dominant hierarchy, to the same extent as prevailed throughout nearly the whole of the rest of Europe. This spirit of independence was sustained throughout the Middle Ages by the immense extension of commercial industry which the fortunate position of Belgium, combined with the energy of her inhabitants, enabled her to develope. While the rest of Europe was engaged in feudal wars and profitless crusades, the peaceful burghers of the Belgian cities were quietly amassing that wealth which gave them individually such importance as free citizens of independent communities, and raised their towns, and eventually their country, to the state of prosperity it maintained till the destruction of their liberties by the Spaniards in the 16th century. These historical circumstances go far to explain the peculiar character observable in the architectural remains of this country, in which we find no trace of any combined national effort. Even the epoch of Charlemagne passed over this province without leaving any impress on the face of the country, nor are there any buildings that can be said to have been called into existence by his influence and power. The great churches of Belgium seem, on the contrary, to have been raised by the individual exertions of the separate cities in which they are found, on a scale commensurate with their several requirements. The same spontaneous impulse gave rise to the town-halls and domestic edifices, which present so peculiar and fascinating an aspect of picturesque irregularity. Even the devastation by the Normans in the 9th and 10th centuries seems to have passed more lightly over this country than any other in the North of Europe. They burned and destroyed indeed many of the more flourishing cities, but they did not occupy them, and when they were gone the inhabitants returned, rebuilt their habitations, and resumed their habits of patient self-supporting labour; and when these inroads ceased there was nothing to stop the onward career of the most industrious and commercial community then established in Europe.