His military success caused the tottering Protestants to call in Gustavus II Adolphus, King of Sweden. Soon, some of Ferdinand's allies began to complain about the excessive power exercised by Wallenstein, as well as the ruthless methods he used to finance his vast army. Ferdinand replied by firing the Bohemian general in 1630. The leadership of the war thenceforth passed to Tilly, who was however unable to stop the Swedish march from northern Germany towards Austria. Some historians directly blame Ferdinand for the large civilian loss of life in the Sack of Magdeburg in 1631: he had instructed Tilly to enforce the edict of Restitution upon the Electorate of Saxony, his orders causing the Belgian general to move the Catholic armies east, ultimately to Leipzig, where they suffered their first substantial defeat at the hands of the Adolphus' Swedes in the First Battle of Breitenfeld (1631).