‘The Four Ages of Poetry’ was published anonymously as the last article in the first and only number of Olliers Literary Miscellany in Prose and Verse by Several Hands, issued by Shelley's publishers, Charles and James Ollier, in the summer of 1820. While the date of composition is not known, Charles Ollier had been acquainted with Peacock since 1817, and he is likely to have solicited a contribution to the new Miscellany in the winter of 1819–20. In a brief note dated 4 September 1820, Peacock asked Ollier to ‘give to my mother whatever may be accruing to me on account of your Miscellany’ (Letters, 1.172). Shelley had been intrigued by the news of Peacock’s essay, and its arrival in Italy prompted him to write A Defence of Poetry in February and March 1821 as the first part of what he intended to be a two-part refutation. But because the Miscellany was not a commercial success, the Olliers never issued a second number, and Shelley never wrote the proposed second part. After Shelley's death in July 1822, Mary Shelley authorized Leigh Hunt to include the ‘Defence’ in The Liberal; or, Verse and Prose from the South (1822–3), which ceased publication after four numbers with Shelley's essay still unpublished. She subsequently planned to include it in a projected edition of her husband's ‘prose pieces’, which she was forced to abandon when her edition of his Posthumous Poems (1824) was suppressed at the insistence of Shelley's father (see Letters, 1.199–200). When she was finally able to publish Shelley’s essay in her edition of his Essays, Letters from Abroad, Translations and Fragments (1840), she omitted the subtitle ‘Remarks Suggested by an Essay Entitled “The Four Ages of Poetry”’ along with Shelley’s other references to Peacock's essay, which had by then been long since forgotten. As edited and published by Mary Shelley, A Defence of Poetry thus appeared to be, as Peacock remarked in a note to one of his friend's letters, ‘a defence without an attack’ (Halliford, 8.500). A few copies of ‘The Four Ages of Poetry’ were privately printed for Peacock's admirer Thomas L’Estrange at Belfast in 1863 (Halliford, 8.491–2), and the essay has since been frequently reprinted and anthologized.