The complex topography of the south German hill country had given rise to an infinite muddle of small states, and at the end of the fifteenth century they agreed, as the people of South France had done centuries before, to 'receive' the Roman Law. This reception was effective over most of the hill country, but not in any considerable part of the plain, a natural consequence of the contrasts already noted, and a further accentuation of them for the succeeding period. In the early sixteenth century came the religious schism, during which the northern plain and the foothill region left the Catholic Church almost _en bloc_, while the people of the hill and valley country of South Germany remained attached to Rome. This, however, by no means adequately describes the territories of the two ecclesiastical systems, for the Roman influence on the Rhine seems to have kept the Ems region largely Catholic, while Protestantism occupied the south along the Cassel-Frankfort line, and spread through Württemberg and the Nürnberg district. The strongly Catholic regions are the Rhine (except about Mainz), the Ems basin, the upper Main area, focusing on Würzburg and Bamberg, and the upper Danube basin (the chief part of Bavaria proper). The Rhine and Danube, with the Roman frontier towns becoming ecclesiastical cities, stand out remarkably in this connexion. {42} The contrasts between north and south have been discussed for the Middle Ages, but they have diminished on the whole in later times. Germany's vernacular literature gained its great impetus from Luther's fine translation of the Bible. He used a Saxon dialect of mixed High and Middle German, and, as in other countries affected by the Great Schism, the language of the Bible became the literary and political language to a large extent, thanks in great part to the practice of requiring every confirmand to learn a portion of Scripture in the vernacular, and to the consequent spread of the reading habit and the demand for books. The growth of newspapers, schools, and public discussions has spread this Middle German as the standard speech of the whole country, but Frisian and Alemannic dialects do still survive within the borders of the new German republic.