For the Austro-Prussian War the Prussians organized their forces into three, and eventually four, field armies.
Helmuth von Moltke, Chief of the Prussian General Staff, assigned four corps to attack the area of the Austria-allied kingdoms of Hanover and Saxony.
[2] Chief of Staff was to be Generalleutnant Konstantin Bernhard von Voigts-Rhetz, who was an intelligent but opinionated officer.
On June 28 both armies operated against Mnichovo Hradiště which turned into the Battle of Münchengrätz.
The First Army had the following order of battle:[6] Commanding General: General der Kavallerie Prince Friedrich Karl of Prussia Chief of Staff: Generalleutnant Konstantin Bernhard von Voigts-Rhetz Quartermaster General: Generalmajor Ferdinand von Stülpnagel Chief of Artillery: Generalmajor Albert von Lengsfeld Chief Engineer: Generalmajor Karl Keiser Commanding General: Generalleutnant Stephan von Schmidt Chief of Staff: Generalmajor Georg von Kameke Directly subordinate to the army Directly subordinate to the army Commanding General: General der Kavallerie Prince Albert of Prussia Chief of Staff: Oberstleutnant Karl von Witzendorff The following detached units also belonged to the corps: