Simplify the following text for a Grade 9 native English-speaking person.
Original: Christian Dior ( 21 January 1905 , Granville , Manche -- 23 October 1957 , Montecatini ) , was an influential French fashion designer , best known as the founder of one of the world 's top fashion houses , also called Christian Dior .
Simplified: Christian Dior ( Granville , Manche , Basse-Normandie , 21 January 1905 â `` Montecatini , Italy , 24 October 1957 ) , was the leading French fashion designer of the post-war world . He was the founder of one of the world 's top fashion houses , the House of Dior ( now Christian Dior ) .