On 25 September 1660 the States of Holland under the prime movers of De Witt, De Graeff, his younger brother Andries de Graeff and Gillis Valckenier resolved to take charge of William III of Oranges education to ensure he would acquire the skills to serve in a future—though undetermined—state function. During the summers the family spent a lot of their time at the Palace Soestdijk, and the sons of De Graeff played with the young William - who became later King of England, Scotland and Ireland and stadtholder of the United Provinces of the Netherlands - at the lake and woods at Palace Soestdijk. After the rampjaar his son Jacob sold it to stadholder William III.