 Sussex married thirdly, on 14 January 1537, Mary Arundell (d. 20 October 1557), the only child of Sir John Arundell (c.1474 – 1545) of Lanherne, Cornwall, and his second wife, Katherine Grenvile, by whom he had two sons, a first-born son baptized 22 March 1538 who died in infancy, and a younger son, Sir John Radcliffe, the subject of this article.Sussex died on 27 November 1542, and his widow, Sir John Radcliffe's mother, Mary, married, on 19 December 1545, as his second wife, Henry FitzAlan, Earl of Arundel (d. 24 February 1580).There were no issue of the marriage.