Mieszko II Lambert of Pöhlde asked the Emperor to defend against the attacks of Mieszko II, promising support in the fight against the Polish ruler. Despite the treaty which secured peace between Poland and Germany, the Emperor soon armed a retaliatory expedition against Mieszko II. Conrad II's army arrived to Lusatia in the autumn of 1029 and began the siege of Bautzen; but the German troops did not receive the promised support of the Lutici tribe and the expedition failed. Threatened by the Hungarians, the Emperor was forced to retreat. Probably in this same year the son of Oldřich, Bretislaus I, attacked and
Mieszko I of Poland poses some problems of interpretation of the information regarding the attack of Margrave Gero on the Slavic tribes, as a result of which he purportedly "subordinated to the authority of the Emperor Lusatia and the Selpuli" (meaning the Słupian tribes) "and also Mieszko with his subjects". According to the majority of modern historians, Thietmar made an error summarizing the chronicle of Widukind, placing the Gero raid there instead of the fighting that Mieszko conducted at that time against Wichmann the Younger. Other sources make no mention of such conquest and of putting the Polans state on the same footing with