Their grandson Johan Willem Friso (1687-1711) became Stadholder in Friesland and Groningen, and in 1702 became the heir of William III of England and thus the founder of the younger House of Orange-Nassau and of the Dutch Royal Family. However, he had to split the Dutch properties with the King of Prussia who also descended from William I. Johan Willem Friso's son, William IV, Prince of Orange, inherited a number of Nassau territories besides his paternal Nassau-Dietz, namely Nassau-Hadamar in 1711, Nassau-Siegen in 1734, and Nassau-Dillenburg in 1739. In 1732, Frederick William I of Prussia left him his Dutch properties, including Huis ten Bosch palace and Het Loo Palace. William IV became stadtholder of the Netherlands in 1747 and reunited all of the Dutch and German possessions of his family (except for Nassau-Weilburg) in his hand, styling himself "Prince of Orange and Nassau".