Within this marshy country, a Polish folk has maintained its own institutions ever since the consolidation of Poles into a distinct people within the drainage area of the Vistula. The only feature of Germanism which took hold in the land was the Protestant religion. The 300,000 Masurians, therefore, present the queer anomaly of a Protestant Polish group. Apart from this peculiarity they are as truly Poles as their land is part of the Vistula basin. With the revival of Polish ideals in recent years the growth of Protestantism in the region has been checked. It is interesting to note that the revulsion of religious feeling had its source in the province of Posen, in the full midst of Teutonic proselytism, and not, as might have been expected, in Russian Poland. The Wends of Germany represent the only intact remnant of the Slav populations which once filled the country. The whole plain country of northern Germany extending from the Elbe to the Vistula had been inhabited by the Wends since early Christian times. The country between the Sale, upper Havel and Spree valleys was probably their original settling ground.[125] They now occupy Lusatia and are sometimes known as Lusatian Serbians. In the Middle Ages the name of Sorabes was given to them. The Germans first began to invade the region in the eleventh century. In the fourteenth, they attained numerical preponderance. The decline of the Slav communities which was accelerated by the Thirty Years’ War, begins about this time. The union of Lusatia with Bohemia helped the Slav cause for a while, but the treaty of Prague, in 1635, by which the country was awarded to Saxony crushed Slavic hopes. At present, the Slavic language has practically disappeared from the region, although the appearance and customs of the inhabitants are more Slav than German. As late as the Middle Ages the Wends occupied an area considerably to the north of their present seat. The eastern valley of the Elbe, as well as Mecklenburg territory, was settled by them before 1160. Charters of this period such as that of the Schwerin bishopric of 1178, or of the cloister of Dargun of 1174, show Slavic place names exclusively. Among signs pointing to a pre-German spread of the Wendish element are the relics of Slavic family names and evidences of the old “Hakenhufen” division of the land in lots of 15 acres. This last proof appears irrefutable and points, upon application, to the former extension of the Wendish element to the very shores of the Baltic.[126] Germanization seems to have been thoroughly accomplished by the second half of the thirteenth century. But even today a great part of the area east of the Elbe must be regarded as a land of German-speaking Slavs. [Illustration: FIG. 41--The area of Wend speech. The dotted patch shows that Kottbus is the center of the district in which the majority of the inhabitants (over 50 per cent) speak the Slav language. In the ruled area the percentage of Wends is less than 50.]