defensive against Polish attack. He aimed at recovering the whole of the last territory between the Elbe and the Oder, once conquered and Christianised by Otto the Great. After suppressing early in 1005 a rising of the Frisians Henry summoned a general levy at Leitzkau, half-way between Magdeburg and Zerbst, on the farther side of the Elbe; and thence, in the middle of August, the king led his army forward through the East Mark, where he was joined the Bavarians under their new Duke, Henry of Luxemburg, and by the Bohemians under Duke Jaromir. But the troops, delayed by false guides who entangled them in the marshes about the Spree, were harassed by ambushed attacks of the enemy. Just before the Oder was reached, the Lyutitzi, headed by their heathen images, attached themselves to the royal host. On pitching camp by the Bobra (Bober) near its junction with the Oder, Henry found Boleslav stationed in strong force at Crossen. The discovery of a ford enabled the king to send over part of his troops, whose appearance drove Boleslav into hasty retreat. The march was continued to within two miles of the city of Posen. But the German army was wearied, and now halted to collect supplies. Its want of vigilance, however, while it was scattered in foraging parties, allowed it to be taken unawares and defeated with heavy loss. This reverse, though not the crushing disaster represented by Polish tradition, disposed Henry to accept an offer made by Boleslav to come to terms. Envoys, with the Archbishop of Magdeburg at their head, were sent to Posen to negotiate with the duke; and a peace, the conditions of which are unknown, was established. The treaty, in any case, was hardly flattering to German pride, for at the utmost Henry can have won from Boleslav no more than a recognition of his authority in the Upper and the Lower Lausitz, and a renunciation of the duke's claim to Bohemia.
During the interval of uneasy peace that followed, Henry's attention was claimed on his western frontier. The Frisian coast was being harried by piratical Northmen; Valenciennes had been seized by the count of Flanders; the kingdom of Burgundy was in a state of turmoil. In Burgundy King Rodolph III, the last male of his house, was struggling vainly to uphold the royal authority against a defiant nobility. To Henry, the son of Rodolph's sister Gisela and his nearest heir, the present unsettlement, which imperilled his chance of succeeding to his uncle's crown, was a matter of serious concern. In 1006, therefore, he made his hand felt in Burgundy. The extent of his intervention is unknown; but the fact is clear that he now took possession of the city of Basle. This step, however brought about, was never reversed; and the sequel shewed it as the earliest in a series by which the independence of the Burgundian kingdom was destroyed.
The incursions of the Northmen, this year and the next, into Frisia were left to the local counts to deal with. It was otherwise when the ambitious Count Baldwin IV of Flanders, one of the mightiest vassals of the West Frankish crown, into whose hands had already fallen the castle
