Question: When did Princess Herzeleide Of Prussia's father die?
Sentence (from "Ernst-Johann Biron, Prince of Courland"): He is also a Knight of Justice( and, since 2008, an honorary commander in the Commandery of Silesia) of the" JohanniterordenJohannine Order"), to which he was admitted in 1940 and whose grand master is his cousin Prince Oskar of Prussia( Prince Ernst- Johann's uncles and grandfather had headed the Order throughout most of the twentieth century).
Relevant evidence: No