The Nassauers held the territory between the Taunus and the Westerwald at the lower and middle Lahn. By 1128, they acquired the bailiwick of the Bishopric of Worms, which had numerous rights in the area, and thus created a link between their heritage at the lower Lahn and their possessions near Siegen. In the middle of the 12th century, this relationship was strengthened by the acquisition of parts of the Hesse-Thüringen feudal kingdom, namely the "Herborner Mark", the "Kalenberger Zent" and the Court of Heimau (Löhnberg). Closely linked to this was the "Lordship of Westerwald", also in Nassau's possession at the time. At the end of the 12th century, the House acquired the "Reichshof" Wiesbaden, an important base in the southwest.