Nevertheless, he soon took the offensive. Marching into Bohemia the Saxons occupied Prague, but John George soon began to negotiate for peace and consequently his soldiers offered little resistance to Wallenstein, who drove them back into Saxony. However, for the present the efforts of Gustavus Adolphus prevented the elector from deserting him, but the position was changed by the death of the king at Lützen in 1632, and the refusal of Saxony to join the Protestant league under Swedish leadership.