What is the name of the paternal grandfather of Lady Margarita Armstrong-Jones ?
Lady Margarita Armstrong-Jones Lady Margarita Elizabeth Rose Alleyne Armstrong-Jones (born 14 May 2002) is the only daughter and youngest child of the Earl and Countess of Snowdon. She is the only granddaughter of Princess Margaret and the first of three granddaughters of the 1st Earl of Snowdon.
Lady Dorothy Macmillan Lady Dorothy Evelyn Macmillan, {'1': ", '2': ", '3': ", '4': "} ("née" Cavendish; 28 July 1900 – 21 May 1966) was a daughter of Victor Cavendish, 9th Duke of Devonshire and Evelyn Cavendish, Duchess of Devonshire and the wife of the British Prime Minister Harold Macmillan.