Since neither of the three kingdoms had any lack of enemies, the three brothers determined to maintain friendly sentiments towards each other and to make common cause for defence against their foes, adjusting their own small differences at a diet of princes (Fürstentag) to be held at short intervals. They met thus for the first time at Diedenheim in 844, then in 847 at Mersen on the Maas [Meuse], and at Mersen again in 851. With them appeared their great vassals, temporal and spiritual. The brothers swore to assist one another with counsel and deed against their enemies, and they directed that their mutual agreement should be put on record and made known among their subjects. But unhappily this act of brotherly concord was deficient in honest purpose, for each one was silently watching and suspecting the others, as though they had been his worst enemies.
LUDWIG TURNS AGAINST CHARLES THE BALD (853-860 A.D.)
[853-855 A.D.]
Up to this time Ludwig had remained the most loyal of the three to this friendly compact; but in the year 853 he allowed his greed of territory to seduce him into an act of treachery towards Charles the Bald. The Aquitanians, who had long struggled under the leadership of Pepin—son of a brother of the three kings who had died young—against union with the dominions of Charles the Bald, appealed to King Ludwig for aid after the death of their prince, proposing that he should either become their king himself or send one of his sons. The war with the Slavs was assuming ever vaster proportions, and Ludwig was unable to quit Germany. He therefore despatched his second son, Ludwig the Younger, with an army to Aquitaine. Charles the Bald was hard pressed by the Northmen at that time, and could only spare a small force to oppose the German troops. But the expedition of the German monarch’s son to Aquitaine was not the success he had anticipated. Only a fraction of the nobility took his part; another party adhered to the son of their late ruler; others, again, held with Charles the Bald. The whole attempt came to nothing. Ludwig was constrained to seek safety in a retreat which bore a strong resemblance to flight. The Aquitanians returned to their allegiance to Charles the Bald when he had set his son, who was still a minor, over them as king, and thus assured their country of a certain degree of independence.
The year 855 summoned King Ludwig to fresh martial enterprises. The Moravians had become restless and menaced the eastern regions of the kingdom with invasion. Ludwig undertook an expedition against Ratislaw, their prince, but without effect, for the enemy took refuge in secure fortified places behind lofty ramparts of earth. After the king had withdrawn the Moravians pressed forward into Germany along the right bank of the Danube, pillaging as they came. Ludwig could do little to protect this part of the country, as the Slavs were stirring again in the northeast. In the succeeding years he had to undertake various small expeditions against the Daleminzians, who dwelt between the Elbe and Mulde, and the Czechs of Bohemia. The results were in most cases inconsiderable, but even in these minor campaigns the German losses in fighting men were heavy. The greatest danger with which Ludwig was at that time menaced loomed from the east. The whole Slavonic world was in a ferment, and strove to gain breathing-space by pressing westwards.
[858-860 A.D.]