Question: Who is Prince Wilhelm Of Prussia (1906–1940)'s maternal grandfather?
Sentence (from "Prince Wilhelm of Prussia (1906–1940)"): Prince Wilhelm of Prussia (Wilhelm Friedrich Franz Joseph Christian Olaf; 4 July 1906 – 26 May 1940) was the eldest child of Crown Prince Wilhelm of Germany and Duchess Cecilie of Mecklenburg-Schwerin.
Relevant evidence: Yes