Seeking to protect the Lutici from Polish invasion, Conrad launched a counter-invasion in 1029 and placed the Polish-held Bautzen under siege. Faced with a potential invasion by Hungary and the failure of the Lutici to provide their promised contingent of troops, Conrad retreated. In 1030, Poland secured an alliance with Hungary, with Stephen I invading Bavaria while Mieszko invaded Saxony. Conrad responded by allying with Yaroslav the Wise, Grand Prince of Kiev, to attack and capture Red Ruthenia on Poland's eastern border. In 1031, Conrad concluded a peace treaty with Hungary by ceding territory in eastern Carinithia to Hungarian control. Freed from the threat of Hungarian attack, the Emperor was able to focus his attention on attacking Poland. Marching on Mieszko in autumn 1031, Conrad laid siege to the Polish held town of Bautzen in the Margraviate of Meissen. Mieszko was crushed by the Holy Roman and Kievan invaders and his exiled brother Bezprym's rebellion. He surrendered to Conrad in the fall 1031. The Treaty of Merseburg procured, that Mieszko return the Margraviate of Meissen and the March of Lusatia to the Empire.