Simone Lucie Ernestine Marie Bertrand de Beauvoir (UK: /də ˈboʊvwɑːr/, US: /də boʊˈvwɑːr/; French: [simɔn də bovwaʁ] (listen); 9 January 1908 – 14 April 1986) was a French existentialist philosopher, writer, social theorist, and feminist activist. Though she did not consider herself a philosopher, nor was she considered one at the time of her death, she had a significant influence on both feminist existentialism and feminist theory.