Marian Evans uses pen name: George Eliot
In 1857, Marian Evans used the pen name, George Eliot, for the first time when she published, "Amos Barton," "Mr Gilfil's Love-story" and "Janet's Repentance" in Edingburgh Magazine. She continued to publish under this pen name when she turned to novel writing and it persisted through to the publication of Middlemarch in 1872.
Eliot, George, and Gregory Maertz. “Chronology.” Middlemarch: A Study of Provincial Life, Broadview Press, Peterborough, Ont., 2004.