Diez

Diez stands where the Aar joins the Lahn, between the Taunus and Westerwald uplands. It was the seat of the counts of Diez and received town rights in 1329, after which walls and five gates were built. The comital dynasty ended in 1386, and later inheritance brought Diez under the landgraves of Hesse.

Diez later became a seat of the Nassau-Dietz family, whose members served as stadtholders in the Netherlands. Princess Albertine Agnes began Oranienstein Palace in 1684 on the site of a former Benedictine convent; it was completed in 1705. During fighting between Austrian and French forces in 1796, retreating French troops burned houses near the Lahn bridge, and fire spread through much of the old town. In 1806 Nassau-Dietz was incorporated into the Duchy of Nassau.