premise: Diana, Princess of Wales's father inherited the title of Earl Spencer.
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 . Edward John `` Johnnie '' Spencer , 8th Earl Spencer , ( 24 January 1924 -- 29 March 1992 ) , styled Viscount Althorp until 1975 , was a British peer and the father of Diana , Princess of Wales .