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