Byron’s Don Juan is one of the greatest poems in the English language. Byron’s friends initially agreed that ‘it will be impossible to publish this’. Byron prevailed, however, and the first two cantos were issued anonymously after much editorial revision. Even in its revised form, Don Juan was perceived as a radical attack on establishment values; the poem has remained a beacon for freedom of speech and retains its power to shock. Since it was published in 1819–24, all printed editions of the poem have used the text prepared by Byron’s publishers, John Murray and John Hunt. This is the first new text of the poem to be printed in two hundred years. The Longman edition is based on a comprehensive line-by-line analysis of the manuscripts, so the text of the poem follows Byron’s own voice, pace and pauses, rather than the grammatical punctuation and more cautious word choice inserted by his nineteenth-century editors. The Longman Don Juan has been annotated afresh, allowing readers to see where Byron left open the choice of words or rhymes, and demonstrating the extraordinary breadth and depth of his literary allusions, topical and cultural references, and socially coded jokes. Textual annotation includes reception history, extensive bibliographies and a detailed chronology, situating Don Juan in the literary, scientific, dramatic, political, musical and social life of the early nineteenth century. A detailed index to the poem and annotation provides an unparalleled resource for students and scholars.