The large Slav element in Rumanian well illustrates the general principle that vocabulary is more easily changed than syntax, a principle one may follow along the Flemish border, where Flemish idiom is maintained with French words, or along the Welsh border, where the form of sentence is so often Welsh though the words be English. Speaking generally we see that there has been on the whole a certain recession of Latin from the old boundaries of the Roman Empire, but that, this apart, that Empire exercised a most potent influence on the speech of its European citizens. The recession was due to mass invasions which, however, as a general rule, penetrated much farther into the Roman domain than one would judge from linguistic evidence alone; in other words, the Latin influence has surged up again, and indeed in one sense those repeated resurgences of Latin feeling have been a main feature of European life in the last twelve or fourteen centuries, while the swaying of the power of Latin and non-Latin elements has {25} been one of the chief causes of war and disunion on the Continent. We may now glance at a few aspects of this swaying of boundaries which are germane to the object of this little book. The Roman Empire in Gaul seems to have been divisible into belts, the southern of which, with its dry and sunny summer, became deeply Romanized in city and country, language and tradition, a zone in which the cities were the residences of all who had sufficient wealth. The middle one, in the main the Paris basin, had fewer cities, but the country was Romanized in language at least. The northern one near the Rhine had strong Roman cities, especially frontier-towns along the river, but the country does not seem to have been Romanized at all deeply. The Franks seem to have been bodies of adventurers seeking new homes, the surplus population of Teutonic regions in what is now north-western Germany. They were not trained to city life, and though the strong frontier-cities survived their passage, the cities of the Paris basin seem to have weakened under their onset, albeit the invaders were not able to break the continuity of civic life in the south. The Paris basin thus became provided with a rural Frankish landed aristocracy around which later on there developed the localism which is called the feudal system. As is the way of aristocracies the rude Franks adopted and modified the Romanized language of the Gauls, making the _langue d'oïl_ the mother of modern French. In the south, older forms persisted less altered as the dialects of the _langue d'oc_.