Diez

The counts of Diez were a medieval comital house in the middle Lahn valley, first documented in 1073 when Count Embricho and his brother sold estates to the Saint Victor chapter at Mainz. Probably installed by the Salian kings, they made Diez Castle their seat and ruled a territory extending into the fertile Goldener Grund; contemporaries called their territory the Golden County.

The Weilnau branch formed its own county in 1302, while the Diez line pledged rights to Nassau, Trier and Katzenelnbogen. Count Gottfried was ruled incapable of governing and placed under guardianship from 1317 to 1332; his son Gerhard VI died feuding against Limburg in 1343.

When the last count, Gerhard VII, died in 1388, the county passed through his daughter Jutta to her husband Adolf of Nassau-Dillenburg. It was later partitioned between Nassau, Eppstein and Trier.