Question: Who is Charles Eugene, 2Nd Duke Of Arenberg's sibling-in-law?
Sentence (from "Charles Eugene, 2nd Duke of Arenberg"): Charles Eugene, 2nd Duke of Arenberg (1633–1681), a Knight of the Order of the Golden Fleece since 1678, became 2nd Duke of Arenberg in 1674 on the death of his half-brother Philippe François, 1st Duke of Arenberg.
Relevant evidence: Yes