A 25 year old who had never been to sea writes a pastiche medieval ballad about a sea-voyage. It remains the best known of all the things he wrote. Readers have responded with a mixture of fascination and puzzlement like that of the Wedding Guest ever since The Ancient Mariner first appeared as the opening poem of Lyrical Ballads, the anonymous volume of which Samuel Taylor Coleridge was joint author with William Wordsworth, in 1798.

By the time Lyrical Ballads went into a second edition (in two volumes) in 1800 The Ancient Mariner had been moved to the penultimate position in the first volume, the position it occupied in later editions in 1802 and 1805. The second edition of Lyrical Ballads identified Wordsworth as the volume's sole author, although its preface mentions Coleridge's five contributions and singles out The Ancient Mariner: ‘the Poem of my friend has indeed great defects’, Wordsworth writes, and goes on to list them. Nearly twenty years after the poem first appeared Coleridge published another different version (adding the Latin epigraph, and the prose gloss in the margins which is neither the first nor last attempt at explanation) in his collected poems, Sibylline Leaves. The text usually reprinted is that from his 1834 collected poems. There are then six published versions of a poem which Coleridge continued to revise, sometimes radically, throughout his life. He seems restlessly compelled to revise a poem within which the Mariner is similarly compelled to repeat and retell his story.

For readers of a poem which casts doubt on where the boundaries lie between dream and actuality, death and life, certainty may come only in the simple referential sentences with which the framing narrative of the poem begins and then with which the mariner begins his narration: ‘It is an Ancient Mariner’ and ‘ “There was a ship” ’. The division of the poem into seven parts points up a structure which is dramatic and which seems to ask to be read in ideal or theological terms. Though it could go on indefinitely, there are two climaxes in the Mariner's account: the shooting of the albatross at the end of Part I – a cliff-hanger – and his blessing of the water snakes at the end of Part IV.