Here his step-son, Ernest II. of Suabia, who claimed the crown of Burgundy, had already risen in rebellion against him. He was not supported even by his own people, and the Emperor imprisoned him in a strong fortress until the Empress Gisela, by her prayers, procured his liberation. Konrad offered to give him back his Dukedom, provided he would capture and deliver up his intimate friend, Count Werner of Kyburg, who was supposed to exercise an evil influence over him. Ernest refused, sought his friend, and the two after living for some time as outlaws in the Black Forest, at last fell in a conflict with the Imperial troops. The sympathies of the people were turned to the young Duke by his hard fate and tragic death, and during the Middle Ages the narrative poem of "Ernest of Suabia" was sung everywhere throughout Germany. Konrad II. next undertook a campaign against Poland, which was wholly unsuccessful: he was driven back to the Elbe with great losses. Before he could renew the war, he was called upon to assist Count Albert of Austria (as the Bavarian "East-Mark" along the Danube must henceforth be called) in a war against Stephen, the first Christian king of Hungary. The result was a treaty of peace, which left him free to march once more against Poland and reconquer the provinces which Henry II. had granted to Boleslaw. The remaining task of his reign, the attachment of Burgundy to the German Empire, was also accomplished without any great difficulty. King Rudolf, before his death in 1032, sent his crown and sceptre to Konrad II., in fulfilment of a promise made when they met at Rome, six years before. Although Count Odo of Champagne, Rudolf's nearest relative, disputed the succession, and all southern Burgundy espoused his cause, he was unable to resist the Emperor. The latter was crowned King of Burgundy at Payerne, in Switzerland, and two years later received the homage of nearly all the clergy and nobles of the country in Lyons. [Sidenote: 1037.] At that time Burgundy comprised the whole valley of the Rhone, from its cradle in the Alps to the Mediterranean, the half of Switzerland, the cities of Dijon and Besançon and the territory surrounding them. All this now became, and for some centuries remained, a part of the German Empire. Its relation to the latter, however, resembled that of the Lombard Kingdom in Italy: its subjection was acknowledged, it was obliged to furnish troops in special emergencies, but it preserved its own institutions and laws, and repelled any closer political union. The continual intercourse of its people with those of France slowly obliterated the original differences between them, and increased the hostility of the Burgundians to the German sway. But the rulers of that day were not wise enough to see very far in advance, and the sovereignty of Burgundy was temporarily a gain to the German power.