However, circumstances forced Ferdinand to recall Wallenstein into the field. The successes of Gustavus Adolphus over General Tilly at the Battle of Breitenfeld and the Lech (1632), where Tilly was killed, and his advance to Munich and occupation of Bohemia, required a vigorous response. It was during this time that Wallenstein had taken inspiration from the reforms of Gustavus Adolphus, instituting harsh discipline by providing rewards for bravery and punishment for disorder, thievery, and cowardice and with this in mind Wallenstein raised a fresh army within a few weeks and took to the field. He drove the Saxon army from Bohemia and then advanced against Gustavus Adolphus, whom he opposed near Nuremberg and, after the Battle of the Alte Veste, dislodged. In November the great Battle of Lützen was fought, in which Wallenstein was forced to retreat but, in the confused melee, Gustavus Adolphus was killed. Wallenstein withdrew to winter quarters in Bohemia.