The campaign in the North
The Northern League’s leaders had met early in the year to outline their plans. At a council of war on 5th April Furst Maurice of Nassau, Furst Ernst von Bamberg, Furst Friedrich von Hessenstein and General von Gehlan of Luneberg. The debate centred around two possible courses of action. The first was an advance from Darmstadt down the Rhine against the Franconian fortress of Hockenheim. This was proposed by Nassau on the grounds it would put them in close proximity to Alsatia. It was opposed by Hessenstein as it would mean crossing the territory of the Prince Archbishop of Mainz, who may oppose them with force and he did not wish to add another enemy quite yet. Hessenstein proposed a march directly south from Darmstadt via Michelstadt towards Heilbronn. This was opposed by Nassau because it would men taking the army through the Odenwald, which he did not consider sustainable.
The course of action eventually adopted was the third, proposed by Bamberg and supported by Gehlan. This proposed a march from Aschaffenburg via Markthiedenfeld to besiege Wurzburg. The fall of this city would effectively isolate his old Duchy of Bamberg. Hessenstein approved positively, Nassau only half-heartedly.
The campaign got under way in May; by the 3rd the Advance Guard of the army under Hessenstein crosses the Franconian border at Wertheim. The main body under Maurice is some way behind and reaches Markgrafthiedenfeld on the 19th. By the 29th May Maurice appears before the walls of Wurzburg and begins his siege operations. To Hessenstein falls the job of covering the siege and he moves to Bad Mergentheim. Here he learns of enemy forces in some strength some ten miles to the south at Dorzbach.
This is the Advance Guard of the Army of the Kralch, commanded by Prinz Friedrich von Franconia, Johann’s third son. The Advance Guard is under the Graf von Hausen who arrived in Dorzbach on the 18th May. Prinz Friedrich, taking some time to gather his army, had originally decided to march on Wurzburg from the south and so moved his main body to Rothenburg-ob-der-Tauber whilst Hausen pinned Hessenstein. Realising the strength of Hessenstein’s force and the vulnerability of the reinforcements under Glt Wiesenstein and GfwM Erffa-Wernburg coming up from Stuttgart, he shifted his force to Bad-Mergentheim, hoping to catch Hessenstein in a vice between his forces and Hausen’s.
The prelude to Hardheim
Once Johann had devined the strategy of the Northern League he ordered the reserve corps of Wiesenstein and Erffa-Wernburg to march out and join the army of Prinz Friedrich. Wiesenstein’s column halted at Brackenheim until the 13th May wracked by an outbreak of dysentery. Originally he marches out for Kupferzell, but only gets halfway when he is instead ordered to the Hessenstein frontier at Miltenberg, Johann intending to use Wiesenstein and Helldorf-Bedra to march on Aschaffenburg. At Bad-Kaiserzell he is struck by yet another bout of dystentery, and only arrives at Hardheim on the 11th June. Here he finds the column of Erffa-Wernburg sent up from Stuttgart.
Hessenstein, aware of Erffa-Wernburg's arrival from his patrols but ignorant of Wiesenstein’s existence, decides to daringly split his force. On the 5th June Generalmajor von Gehlan is commanded to take the Luneberg, Bamberg and Nassau troops and attack Erffa-Wernburg at Hardheim before he can link up with Hausen. Meanwhile Hessenstein would try to maintain a show of strength before Hausen.
Von Gehlan proved he was not up to the task. He takes ten days to reach Hardheim, and by the time he does Wiesenstein has been there for three full days. The scene is set for a battle.