Question: Who is the maternal grandfather of Arthur Hill, 3Rd Marquess Of Downshire?
Sentence (from "Mary Hill, Marchioness of Downshire"): She was born Mary Sandys, daughter of Colonel Martin Sandys (fourth son of Samuel Sandys, 1st Baron Sandys) and his wife Mary Trumbull (only child and heiress of William Trumbull, son of Sir William Trumbull).
Relevant evidence: Yes