The ill-fated mountaineer George Mallory's only book was "Boswell the Biographer"?
Rudolf Ulrich van SporkenBorn 1696
Married (1721) to Susanna van Slingelandt (1700-1737). Envoy extraordinary to the Hague for Hannover.
Life with Boswell:
Boswell visited the Baron on December 28, 1763, at The Hague.
Sources: Familysearch and Boswell in Holland 1763-64, p. 107