What is the name of the paternal grandfather of Lady Margarita Armstrong-Jones ?
David Armstrong-Jones, 2nd Earl of Snowdon:  The son of Princess Margaret, Countess of Snowdon, and of Antony Armstrong-Jones, 1st Earl of Snowdon, he is a grandson of King George VI and is 18th in line of succession to the British throne, the first in line who is not a descendant of Queen Elizabeth II.
i don't know