Question: Who is Charles Eugene, 2Nd Duke Of Arenberg's sibling-in-law?
Sentence (from "Philippe François, 1st Duke of Arenberg"): When he died in December 1674, the title passed to his half-brother, Charles Eugene, Duke of Arenberg, (1633–1681), who was promoted to become a Knight of the Order of the Golden Fleece in 1678.
Relevant evidence: No