Shelley completed her writing in May 1817, and Frankenstein; or, The Modern Prometheus was first published on 11 March 1818 by the small London publishing house of Lackington, Hughes, Harding, Mavor, & Jones. It was issued anonymously, with a preface written for Mary by Percy Bysshe Shelley and with a dedication to philosopher William Godwin, her father. It was published in an edition of just 500 copies in three volumes, the standard "triple-decker" format for 19th-century first editions.
The second edition of Frankenstein was published on 11 August 1822 in two volumes (by G. and W. B. Whittaker) following the success of the stage play Presumption; or, the Fate of Frankenstein by Richard Brinsley Peake; this edition credited Mary Shelley as the author.
On 31 October 1831, the first "popular" edition in one volume appeared, published by Henry Colburn & Richard Bentley. This edition was heavily revised by Mary Shelley, partially because of pressure to make the story more conservative, and included a new, longer preface by her, presenting a somewhat embellished version of the genesis of the story. This edition tends to be the one most widely read now, although editions containing the original 1818 text are still published. Many scholars prefer the 1818 text, arguing that it preserves the spirit of Shelley's original publication (see Anne K. Mellor's "Choosing a Text of Frankenstein to Teach" in the W.W. Norton Critical edition).