Soon afterward, on 31 March 1310, John purchased the hereditary possessions of the Lords of Merenberg in the area from Harrad VII (d. 1328), the last male member of the dynasty.
[1] Like his father, John fought in long and bitter feuds against the local nobility, in particular the Lords of Dernbach and Bicken, to impose his sovereignty.
On 26 June 1312, a peace treaty was signed by Landgrave Otto I of Hesse and the brothers Henry, Emicho and John of Nassau.
They agreed to stop building castles against each other and the Nassaus promised not to infringe on in the rights the Lords of Dernbach and Wilnsdorf had possessed during their father's lifetime.
Matthias formed an alliance with the nobility in central Hesse and the Wetterau area, including the Nassau family.
Landgrave Otto I died in January 1328, and his son Henry II continued the feud.
Later, Emicho renounced his rights, and Henry gave Nassau-Dillenburg to his eldest son, Otto II.