Complex sentence: He married secondly Anne Chedworth, the daughter of William Chedworth, Clerk of the Common Council of London, by whom he had a son, John, who predeceased him, and a daughter, Joan.
Split into simpler sentences: He married secondly Anne Chedworth, the daughter of William Chedworth, Clerk of the Common Council of London. He had a son, John, who predeceased him, and a daughter, Joan.