The Siege of Heidelberg or the Imperial-Spanish capture of Heildelberg took place from 23 July to 19 September 1622, at Heidelberg, Electorate of the Palatinate, between the Imperial-Spanish army led by Johan Tzerclaes, Count of Tilly and Don Gonzalo Fernández de Córdoba against the Anglo-Protestant forces of Frederick V, Elector Palatine, commanded by Sir Gerard Herbert and Sir Horace Vere during the Palatinate campaign, in the context of the Thirty Years' War. Wikipedia