Nassau-Wiesbaden under Count Adolf I (1307–1370), eldest son of Gerlach. It eventually fell back to Nassau-Weilburg in 1605. Counts of Nassau-Saarbrücken (1429–1797) Philipp I ruled both Nassau-Saarbrücken and Nassau-Weilburg and in 1393 inherited through his wife Johanna of Hohenlohe the lordships Kirchheimbolanden and Stauf. He also received half of Nassau-Ottweiler in 1393 and other territories later during his reign. After his death in 1429 the territories around Saarbrücken and along the Lahn were kept united until 1442, when they were again divided among his sons into the lines Nassau-Saarbrücken (west of the Rhine) and Nassau-Weilburg (east of the Rhine), the so-called Younger line of Nassau-Weilburg. In 1507 Count John Ludwig I significantly enlarged his territory. After his death in 1544 the county was split into three parts, the three lines (Ottweiler, Saarbrücken proper and Kirchheim) were all extinct in 1574 and all of Nassau-Saarbrücken was united with Nassau-Weilburg until 1629. This new division however was not executed until the Thirty Years' War was over and in 1651 three counties were established: Nassau-Idstein, Nassau-Weilburg and Nassau-Saarbrücken. Only eight years later, Nassau-Saarbrücken was again divided into: Nassau-Saarbrücken proper, fell to Nassau-Ottweiler in 1723 Nassau-Ottweiler, fell to Nassau-Usingen in 1728 Nassau-Usingen In 1735 Nassau-Usingen was divided again into Nassau-Usingen and Nassau-Saarbrücken. In 1797 Nassau-Usingen finally inherited Nassau-Saarbrücken, it was (re-)unified with Nassau-Weilburg and raised to the Duchy of Nassau in 1806. The first Duke of Nassau was Frederick August of Nassau-Usingen who died in 1816. Wilhelm, Prince of Nassau-Weilburg inherits the Duchy of Nassau. But, territories of Nassau Saarbrücken was occupied by France in 1793 and was annexed as Sarre department in 1797. Finally County of Nassau-Saarbrücken was part of Prussia in 1814. After Henry Louis's death, Nassau-Saarbrücken fell to Charles William, Prince of Nassau-Usingen until Adolph came of age in 1805. Princes of Nassau-Usingen (1659–1816) The origin of the county lies in the medieval county of Weilnau that was acquired by the counts of Nassau-Weilburg in 1602. That county was divided in 1629 into the lines of Nassau-Weilburg, Nassau-Idstein and Nassau-Saarbrücken that was divided only 30 years later in 1659. The emerging counties were Nassau-Saarbrücken, Nassau-Ottweiler and Nassau-Usingen. At the beginning of the 18th century, three of the Nassau lines died out and Nassau-Usingen became their successor (1721 Nassau-Idstein, 1723 Nassau-Ottweiler und 1728 Nassau-Saarbrücken). In 1735 Nassau-Usingen was divided again into Nassau-Usingen and Nassau-Saarbrücken. In 1797 Nassau-Usingen inherited Nassau-Saarbrücken. In 1816, Nassau-Usingen