In the days of Charlemagne, Germany’s eastern boundary was extended to the Elbe, and beyond it to Holstein, but it was not until four centuries later, that is, in the reign of Frederick Barbarossa, that the Baltic was reached, the southern borders of which sea, now constituting Mecklenburg, Pomerania, and Prussia, having theretofore been inhabited chiefly by Slavonic and Lithuanian peoples.  The credit for this increase of power is due primarily to the Saxon duke Henry the Lion, who, while the Emperor was engaged in maturing and executing mighty plans of world conquest, developed upon this virgin soil an extraordinary colonial activity, transplanting hither German peasants, burghers, and priests, and with them German customs and Christian civilization.  In this way there arose about the year A.D. 1200, upon soil wrested from the Slavs, a number of promising towns, foremost among which was Lubeck, a place endowed by Duke Henry with municipal rights especially designed to promote commercial intercourse and affording liberal and far-reaching privileges to the counsellors and burghers.  Soon thereafter the rapidly developing neighboring cities of Wismar, Rostock, Stralsund, Greifswald, Anklam, and Stettin, usually called “the Wendish cities,” became participants in the constitution thus granted.  The territory now grew rapidly.  In the course of the thirteenth century, the then pagan country of Prussia and the present Baltic provinces of Russia were conquered by the Teutonic knights and kindred orders and were occupied and settled.  The same historical process which took place in Greece, and in more recent times in America, also repeated itself here:  the youthful colonial offshoots overcame the narrowing and confining influence of the mother country, yet reacted favorably upon it by virtue of that vivifying influence, due to more rapid and exuberant growth.

In the mean time the other countries contiguous to the North and Baltic seas, that is, Russia, Sweden, Norway, Denmark, and England, had become converted to Christianity.  Some of them, indeed, had embraced the Christian creed several centuries prior to this time.  The natural consequence was that a lively intercourse was cultivated upon the two seas, especially after the crusades, which enterprises, by opening new avenues of commerce and increasing the knowledge concerning numerous articles of utility, had greatly augmented the demands of the people of the Occident.  The extraordinary development of trade on the Baltic, indeed, vividly recalls the ancient commercial activity on the Mediterranean; and the phrase, “a basin fruitful of culture,” often applied to the latter region, may with equal justice be applied also to the former.  In the beginning, Russians, Danes, and Englishmen participated in the active trade conducted on the northern littoral.  Eventually, however, they were displaced by their German rivals.  As the northern nations upon their acceptance of Christianity had once before formed their political and social institutions upon German models, so they now, in such cities as Stockholm, Bergen, Copenhagen, and others, became subject to the cultural and, above all, the commercial influence of the German burgher.