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.