|Catholic forces under the command of Count Von Tilly captured the fortress of Magdeburg in present day Germany on May 20, 1613. There followed a Catholic massacre of the Protestant population of the city and surrounding areas. This caused the populations of Bradenburg and Saxony to join the Protestant coalition. After the imperial forces captured Leipzig, Protestant forces led by Gustav II Adophus moved south to engage the Catholics. On September 18th just north of Leipzig the two armies met in battle, The outcome of the battle was the first Protestant victory in the 30 years war.