Complex sentence: His later years had been spent in the house of his son-in-law, Sir Ralph Whitfield, and he was survived by son John Spelman and, daughter Catherine who married a Secretary of State.
Split into simpler sentences: His later years were spent in the house of his son-in-law, Sir Ralph Whitfield. He was survived by his son, John Spelman, and a daughter, Catherine, who married a Secretary of State.