The progress of the _Monumenta_ stimulated the production of other works of a like nature, and among the smaller collections of authorities which appeared during the 19th century two are worthy of mention. These are the _Fontes rerum Germanicarum_, edited by J. F. Böhmer (Stuttgart, 1843-1868), a collection of sources of the 12th, 13th and 14th centuries, and the _Bibliotheca rerum Germanicarum_, edited by Ph. Jaffé (Berlin, 1864-1873). Another development followed the production of the _Monumenta_, this being the establishment in most of the German states of societies the object of which was to foster the study of local history. Reference may be made to a _Verein_ for this purpose in Saxony and to others in Silesia and in Mecklenburg. Much has also been done in Prussia, in Brandenburg, in Bavaria, in Hanover, in Württemberg and in Baden, and collections of authorities have been made by competent scholars, of which the _Geschichtsquellen der Provinz Sachsen und angrenzender Gebiete_ (Halle, 1870, fol.), which extends to forty volumes, the smaller _Scriptores rerum Prussicarum_ (Leipzig, 1861-1874), and the seventy-seven volumes of the _Publikationen aus den königlichen preussischen Staatsarchiven, veranlasst und unterstützt durch die königliche Archiverwaltung_ (Leipzig, 1878, fol.), may be cited as examples. The cities have followed the same path and their archives are being thoroughly examined. In 1836 an _Urkundenbuch_ of Frankfort was published, and this example has been widely followed, the work done in Cologne, in Bremen and in Mainz being perhaps specially noticeable. Moreover an historical commission at Munich has published twenty-eight volumes in the series _Die Chroniken der deutschen Städte vom 14. bis ins 16. Jahrhundert_ (Leipzig, 1862, fol.). Lastly, many documents relating to the great families of Germany, among them those of Hohenzollern and of Wittelsbach, have been carefully edited and given to the world. With this great mass of material collected, sifted and edited by scholars of the highest standing it is not surprising that modern works on the history of Germany are stupendous in number and are generally of profound learning, and this in spite of the fact that some German historians--Gregorovius, Pauli and Lappenberg, for example--have devoted their time to researches into the history of foreign lands. The earliest period is dealt with by K. Zeuss in _Die Deutschen und die Nachbarstämme_ (Munich, 1837; new ed., Göttingen, 1904); and then by F. Dahn in his _Urgeschichte der germanischen und romanischen Völker_ (Berlin, 1880-1889) and his _Die Könige der Germanen_, volumes of which have appeared at intervals between 1861 and 1909.