Vladimir Vladimirovich Nabokov (Russian: Влади́мир Влади́мирович Набо́ков [vlɐˈdʲimʲɪr vlɐˈdʲimʲɪrəvʲɪtɕ nɐˈbokəf] (listen); 22 April [O.S. 10 April] 1899 – 2 July 1977), also known by the pen name Vladimir Sirin (Russian: Влади́мир Си́рин), was a Russian and American novelist, poet, translator and entomologist. His first nine novels were written in Russian (1926–38), but he achieved international prominence after he began writing English prose. Nabokov became an American citizen in 1945.