Ethel Lilian Voynich, née Boole, was born in Ballintemple, a suburb of Cork, Ireland. Her parents were the English mathematician George Boole, the originator of Boolean logic, and his wife Mary Everest, later an educator and writer. When she was six months old, her father died, and her mother took her five daughters to England, where she was appointed librarian at Queen's College, London. She taught Ethel and her sisters mathematics, geometry and logic. At age 18, Ethel received a small inheritance that enabled her to study piano and musical composition at the Hochschule fur Musik in Berlin in 1882-1885. During this period, she became attracted to radical leftist politics. On her return to London, she studied Russian with the revolutionary Sergei Kravchinsky, a family friend, who encouraged her to travel to Russia. In 1887, she got a job as a governess in St. Petersburg, where she stayed with Kravchinsky's sister-in-law, Preskovia Karauloff. Through her, she became associated with the revolutionary group known as the Narodniks. After her return home, she co-founded the Society of Friends of Russian Freedom with Kravchinsky, and helped to edit Free Russia, the group's publication. She met Wilfrid Michael Voynich (born Wilfrid Michał Habdank-Wojnicz), a book dealer and Russian revolutionary who had escaped from Siberia and fled to England. They began living together by 1895 and she called herself Mrs. Voynich; the couple married in 1902. In 1897, she published the novel The Gadfly, which was an instant international bestseller. In Russia, it was later adapted into a 1955 film and a 1980 television series. She published three more novels, though none matched the huge popularity of the first. She also composed music and created adaptations and transcriptions of exising works. The couple emigrated in 1920 to the USA, settling in New York City, where she founded a music school and worked as a translator of Russian, Polish and French works into English.