premise: Diana, Princess of Wales's father inherited the title of Duke of Wellington.
hypothesis: Diana , Princess of Wales ( Diana Frances ; née Spencer ; 1 July 1961 -- 31 August 1997 ) , was the first wife of Charles , Prince of Wales , who is the eldest child and heir apparent of Queen Elizabeth II . Diana was born into a family of British nobility with royal ancestry and was the fourth child and third daughter of John Spencer , Viscount Althorp , and the Honourable Frances Roche . In 1975 , after her father inherited the title of Earl Spencer , she became known as Lady Diana Spencer .