‘In future this is all your master will get from us,’ he exclaimed, and the answer, as he expected, provoked an immediate invasion. Instead of being able to lay waste the countryside as of old, however, the Hungarians now found ‘burgs’ well fortified and provisioned that they could neither take nor leave with safety in their rear. When at last they met Henry in pitched battle, they broke and fled before his onslaught, declaring that the golden banner of St. Michael, carried at the head of his troops, had by some wizardry contrived their ruin. Besides repulsing invaders, Henry the Fowler imposed his will to a considerable extent over his rebellious baronage. In another chapter[10] we have noticed how he instituted ‘the order of knighthood’ as a way of harnessing to his service the restless energy of the younger sons of the nobles: he also tried to strengthen the middle classes as a counterpoise to the baronage by encouraging the construction of walled towns for the protection of merchants, while he would hold his councils rather in towns than in the woods like his predecessors, in order to attract people to settle there. Many of the Marks owe their origin to Henry’s policy of strengthening the border provinces; and in this and in his determination to subdue the Hungarians he found an able successor in his son Otto I. [Sidenote: Otto ‘the Great’] Otto’s reign might from one aspect be called a history of wars. First there were foreign wars--the subjugation of Denmark, whose king became a German vassal; the reconquest and conversion of Bohemia; and also a series of campaigns against the Hungarians, resulting at last in 955 in a victory at Augsburg so complete that never again the hated invaders dared to cross the border save in marauding bands. But besides fighting against foreign neighbours Otto had a continual struggle at home in order to reassert the authority of the crown over the great duchies such as Lotharingia and Bavaria. When he was able to do so he would replace the most turbulent of the dukes by members of his own family, or he would make gifts of large estates to bishops, hoping in this way to provide himself with loyal tenants-in-chief. In this, however, he was not successful, for he found the feudal bishops amongst his worst enemies; so that he turned at last for help to the new type of Churchman, bred by the Cluniac reform movement--men of learning and culture, monks in their religious observances, statesmen in their outlook. These were at one with him in his desire for a united Germany and a purer Church; but Otto was faced by a great problem when he wished to reform and control his bishops. How far were the German clergy under his jurisdiction? How far did they owe obedience only to Rome, as they claimed if he tried to exert his authority over them?