In turn, the rebellious German princes met at Trebur in October and resolved upon his deposition, if he would not be able to obtain the revocation of the ban within a year.

By his Walk to Canossa in January 1077, the king received absolution, nevertheless the princes elected Rudolf of Rheinfelden anti-king on March 15.

Henry successfully drew off the Saxons by feigning a move toward Goslar, while his main army approached Erfurt eastwards along Saxony's southern border.

Henry plundered the city and proceeded to Naumburg, hoping to meet up with the other half of his forces on the Saale or Elster rivers.

The Saxon commander Otto of Nordheim led these forces on a direct assault across the swampy Gruna.

Rudolf died of his wounds the next day and his body was laid out in Merseburg Cathedral, where the severed hand is still kept.

He declared the loss of Rudolf's Schwurhand, a judgement of God, further weakening the support of the prince's rebellion.