Question: Jonkheer Douwe Sirtema van Grovestins (Leeuwarden, Brussels, 1710 – February 26, 1778) was a Frisian courtier at the court of which stadtholder, that was the first hereditary Stadtholder of all the United Provinces?
Sentence (from "William IV, Prince of Orange"): William IV, Prince of Orange-Nassau (Willem Karel Hendrik Friso; 1 September 1711 – 22 October 1751) was the first hereditary Stadtholder of all the United Provinces.
Relevant evidence: Yes