In an effort to destroy the center of rebellion and to maintain the unity of the empire, emperor Henry IV attempted to lift the siege.

[2][3] Imperial army, numbering about 20,000 (according to unverifiable contemporary accounts), was largely composed of armed peasants and town militia, while rebel forces, numbering some 10,000, had a larger proportion of mounted knights.

[1] Armies met on 11 August 1086 at Pleichfeld, a village 3 km (2 mi) north of Würzburg.

Loyalist army, composed mostly of untrained peasants and armed citizens, broke and fled after the first charge.

Their swift defeat was attributed by chroniclers to treason amongst the emperor's own knights, who accepted a bribe and changed sides in the thick of battle.