The frontier state of Brandenburg had been originally founded by Charlemagne to defend his eastern possessions against raids of the wild Saxon tribes. The Wends, a Slavic tribe which inhabited that region, were subjugated during the tenth century and their market-place, by the name of Brennabor, became the centre of and gave its name to the new province of Brandenburg. During the eleventh, twelfth, thirteenth and fourteenth centuries, a succession of noble families exercised the functions of imperial governor in this frontier state. Finally in the fifteenth century, the House of Hohenzollern made its appear-ance, and as Electors of Brandenburg, commenced to change a sandy and forlorn frontier territory into one of the most efficient empires of the modern world. These Hohenzollerns, who have just been removed from the historical stage by the combined forces of Europe and America, came originally from southern Germany. They were of very humble origin. In the twelfth century a certain Frederick of Hohenzollern had made a lucky marriage and had been appointed keeper of the castle of Nuremberg. His descendants had used every chance and every opportunity to improve their power and after several centuries of watchful grabbing, they had been appointed to the dignity of Elector, the name given to those sovereign princes who were supposed to elect the Emperors of the old German Empire. During the Reformation, they had taken the side of the Protestants and the early seventeenth century found them among the most powerful of the north German princes. During the Thirty Years War, both Protestants and Catholics had plundered Brandenburg and Prussia with equal zeal. But under Frederick William, the Great Elector, the damage was quickly repaired and by a wise and careful use of all the economic and intellectual forces of the country, a state was founded in which there was practically no waste.