German kings, in consequence of this external menace, had to rely for the defence of their frontiers upon the military power of their great vassals. They were even forced to create large estates called ‘Marks’ (march-lands) upon their northern and eastern borders to act as national bulwarks. Over these ruled ‘Margraves’ (‘grafs’ or Counts of the Mark) with a large measure of independence. Modern Prussia was once the Mark of Brandenburg, a war state created against the Slav; Austria the Mark placed in the east between Bavaria and the Hungarians; Schleswig the Mark established to hold back the Danes. Yet another cause told for disruption: the fact that when the Carolingian line came to an end in Germany early in the tenth century the practice sprang up of electing kings from among the chief princes and dukes. Though this plan worked well if the electors made an honest choice, yet it gave the feudal baronage a weapon, on the other hand, if they wished to strike a bargain with a would-be ruler or to appoint a weakling whose authority they could undermine. [Sidenote: Henry ‘the Fowler’] The first of the elected kings of Germany was Conrad of Franconia, during whose reign the feudal system took strong root, and who ruled rather through his barons than in opposition to their wishes. On his death-bed he showed his honest desire for the welfare of Germany. ‘I know,’ he declared, ‘that no man is worthier to sit on my throne than my enemy Henry of Saxony.... When I am dead, take him the crown and the sacred lance, the golden armlet, the sword, and the purple mantle of the old kings.’ The princes, who followed his advice, found their new ruler out hawking on the mountain side, and under the nickname Henry ‘the Fowler’ he became their king and one of Germany’s national heroes. In his untiring struggle against invaders Henry I recalls the Anglo-Saxon Alfred ‘the Great’, and like Alfred he was at first forced to fly before his enemies. To the disgust of the great dukes he bought a nine years’ peace from the Hungarians by paying tribute; but when the enemy went away he at once began to build castles or ‘burgs’, and filled them with soldiers under the command of ‘burgraves’. These castles were placed all along the frontiers, and gradually villages and towns gathered round them for safety. In the tenth year the Hungarians came as usual to ask for the tribute money, but Henry ordered a dead dog to be thrown at their messenger’s feet.