Second Margrave War participant Prince-Bishopric of Würzburg
The war
Albert's first targets were Brandenburg-Kulmbach's immediate neighbors, starting with the Imperial City of Nuremberg. An initial siege attempt was unsuccessful, so Brandenburg-Kulmbach forces relentlessly raided Nuremberg's hinterland, in the process capturing Forchheim and its fortress. Nuremberg finally surrendered to Brandenburg-Kulmbach on June 19, 1552. Brandenburg-Kulmbach was also able to capture the Imperial City of Schweinfurt, which would become an important base for further conquests. Albert entered extortive treaties with the Prince-Bishoprics of Würzburg and Bamberg, requiring them to make him large payments and surrender land to avoid conquest. Eventually, he conquered Bamberg outright. These treaties were not recognized by Emperor Charles V, who placed Albert under an Imperial ban. However, since Charles was partially reliant on Albert's troops at his Siege of Metz, the ban was reversed, and Charles tacitly allowed Albert to carry on.In the summer of 1552, Albert marched into the Rhineland in an attempt to join his armies with those of the Kingdom of France against the Emperor. Albert started conflicts with the Electorates of Mainz and Trier along the way, also feuding with Speyer, Worms, Oppenheim, Verdun, and Frankfurt, among others. He demanded 150,000 Gulden from the Prince-Bishopric of Speyer, when it did not oblige, he destroyed the castles of Madenburg and Hambach. The ruins of Hambach Castle would later become an early symbol of the German nationalist and democratic movement. The Peace of Passau, which provided a conclusion to the Second Schmalkaldic war in August 1553, failed to validate Albert's territorial ambitions, motivating him to continue fighting.
Albert's destructive path through the Holy Roman Empire made him the enemy of many Princes, who eventually formed several leagues against him. Brandenburg-Kulmbach's immediate neighbors formed a Franconian League, while his opponents in other areas formed a Heidelberg League which quickly allied itself with the Franconian one. With Brandenburg-Kulmbach's troops caught up in Lower Saxony, where Albert was levying troops, armies from Nuremberg, Würzburg and Bamberg reconquered castles and land that had been seized by Albert earlier in Franconia, while the armies of Brunswick and Saxony made their way to Schweinfurt.