Rupert, Count of Nassau-Sonnenberg

Gerlach's widow Irmengard retired to Liebenau monastery, near Worms, where she became a Dominican nun.

Rupert claimed these fiefs, and joined the Star Covenant, an alliance of knights against Landgrave Henry II of Hesse.

He managed to keep his Sonnenberg Castle intact, whereas the town of Nassau was so badly damaged during the fighting that it was uninhabitable for a while.

In 1382, Rupert and the Counts of Solms-Burgsolms expanded Greifenstein Castle and added the characteristic twin towers.

After the feud he fought in the Hattstein War on the side of the cities in the Rhine/Wetterau region, against the high nobility in the area.