The feud was named after the knightly House of Dernbach, a powerful Ganerbschaft (jointly-owned inheritance) with almost sovereign rights.
The Dernbachers, along with the Lords of Bicken (the present-day administrative center of Mittenaar), carried the primary burden of opposing Nassau’s quest for the territorial dominion of the area.
Parallel with this conflict, Count Henry II was also fighting a vendetta against the Knight of Wilnsdorf in the Siegerland, who soon allied himself with the Dernbachers.
Otto undertook to further expand the castle, to bring the city under its protection to prevent it from falling into the hands of Nassau.
It committed both sides in the future to no longer build castles against each other, and the Nassaus conceded that they could not restrict the rights are the Lords of Dernbach and Wilnsdorf.
The Landgrave thus lost important bases in the disputed territory and so in 1326 built the new Hessenwald Castle, near the present site of Roth at the Heligenberg, strategically advantageously located on the remaining possessions of the Lords of Bicken, and likewise protecting the Breidenbacher area.
However, Landgrave Henry II of Hesse later won the battle on 10 August 1328 at Wetzlar, in which Count John of Nassau-Dillenburg (a son of Otto I) was killed.
On 21 May 1336 an agreement was also concluded between the Lords of Bicken and Nassau, in which they sold Hainchen Castle (with the bulk of the property belonging to it) to the Count, but received rights to reign around Ebersbach.
On 21 April 1486, a Heidenrich of Dernbach sold his remaining serfs in the Nassau area to the local count for a low price.