His confirmation inspired him to write some religious poems published in that paper. In 1763, a cross which had adorned the churchyard of St Mary Redcliffe for upwards of three centuries was destroyed by a churchwarden. The spirit of veneration was strong in Chatterton, and he sent to the local journal on 7 January 1764 a satire on the parish vandal. He also liked to lock himself in a little attic which he had appropriated as his study; and there, with books, cherished parchments, loot purloined from the muniment room of St Mary Redcliffe, and drawing materials, the child lived in thought with his 15th-century heroes and heroines.

To bring his hopes to life, Chatterton started to look for a patron. At first, he was trying to do so in Bristol where he became acquainted with William Barrett, George Catcott and Henry Burgum. He assisted them by providing Rowley transcripts for their work. The antiquary William Barrett relied exclusively on these fake transcripts when writing his History and Antiquities of Bristol (1789) which became an enormous failure. But since his Bristol patrons were not willing to pay him enough, he turned to the wealthier Horace Walpole. In 1769, Chatterton sent specimens of Rowley’s poetry and “The Ryse of Peyncteynge yn Englade” to Walpole who offered to print them “if they have never been printed.” Later, however, finding that Chatterton was only 16 and that the alleged Rowley pieces might have been forgeries, he scornfully sent him away.

He wrote political letters, eclogues, lyrics, operas and satires, both in prose and verse. In June 1770, after nine weeks in London, he moved from Shoreditch, where he had lodged with a relative, to an attic in Brook Street, Holborn (now beneath Alfred Waterhouse’s Holborn Bars building). He was still short of money; and now state prosecutions of the press rendered letters in the Junius vein no longer admissible, and threw him back on the lighter resources of his pen. In Shoreditch, he had shared a room; but now, for the first time, he enjoyed uninterrupted solitude. His bed-fellow at Mr Walmsley’s, Shoreditch, noted that much of the night was spent by him in writing; and now he could write all night. The romance of his earlier years revived, and he transcribed from an imaginary parchment of the old priest Rowley his “Excelente Balade of Charitie.” This poem, disguised in archaic language, he sent to the editor of the Town and Country Magazine, where it was rejected.

While walking along St Pancras Churchyard, Chatterton much absorbed in thought, took no notice of an open grave, newly dug in his path, and subsequently tumbled into it. His walking companion, upon observing this event, helped Chatterton and told him in a jocular manner that he was happy in assisting at the resurrection of genius. Chatterton replied, “My dear friend, I have been at war with the grave for some time now.” Chatterton died by suicide three days later. On 24 August 1770, he retired for the last time to his attic in Brook Street, carrying with him the arsenic which he drank, after tearing into fragments whatever literary remains were at hand. He was 17 years and nine months old. There has been some speculation that Chatterton may have taken the arsenic as a treatment for a venereal disease, as it was commonly used for such at that time.

It was after Chatterton’s death that the controversy over his work began. Poems supposed to have been written at Bristol by Thomas Rowley and others, in the Fifteenth Century (1777) was edited by Thomas Tyrwhitt, a Chaucerian scholar who believed them genuine medieval works. However, the appendix to the following year’s edition recognises that they were probably Chatterton’s own work. Thomas Warton, in his History of English Poetry (1778) included Rowley among 15th-century poets, but apparently did not believe in the antiquity of the poems. In 1782 a new edition of Rowley’s poems appeared, with a “Commentary, in which the antiquity of them is considered and defended,” by Jeremiah Milles, Dean of Exeter.

The controversy which raged round the Rowley poems is discussed in Andrew Kippis, Biographia Britannica (vol. iv., 1789), where there is a detailed account by George Gregory of Chatterton’s life (pp. 573–619). This was reprinted in the edition (1803) of Chatterton’s Works by Robert Southey and Joseph Cottle, published for the benefit of the poet’s sister. The neglected condition of the study of earlier English in the 18th century alone accounts for the temporary success of Chatterton’s mystification. It has long been agreed that Chatterton was solely responsible for the Rowley poems; the language and style were analysed in confirmation of this view by W. W. Skeat in an introductory essay prefaced to vol. ii. of The Poetical Works of Thomas Chatterton (1871) in the “Aldine Edition of the British Poets.” The Chatterton manuscripts originally in the possession of William Barrett of Bristol were left by his heir to the British Museum in 1800. Others are preserved in the Bristol library.

Chatterton’s genius and his death are commemorated by Percy Bysshe Shelley in Adonais (though its main emphasis is the commemoration of Keats), by William Wordsworth in “Resolution and Independence”, by Samuel Taylor Coleridge in “Monody on the Death of Chatterton”, by Dante Gabriel Rossetti in “Five English Poets”, and in John Keats’ sonnet “To Chatterton”. Keats also inscribed Endymion “to the memory of Thomas Chatterton”. Two of Alfred de Vigny’s works, Stello and the drama Chatterton, give fictionalized accounts of the poet; in the former, there is a scene in which William Beckford’s harsh criticism of Chatterton’s work drives the poet to suicide. The three-act play Chatterton was first performed at the Théâtre-Français, Paris on 12 February 1835. Herbert Croft, in his Love and Madness, interpolated a long and valuable account of Chatterton, giving many of the poet’s letters, and much information obtained from his family and friends (pp. 125–244, letter li.).

In 1886, architect Herbert Horne and Oscar Wilde unsuccessfully attempted to have a plaque erected at Colston’s School, Bristol. Wilde, who lectured on Chatterton at this time, suggested the inscription: “To the Memory of Thomas Chatterton, One of England’s Greatest Poets, and Sometime pupil at this school.”

In 1928, a plaque in memory of Chatterton was mounted on 39, Brooke Street, Holborn, bearing the inscription below. The plaque subsequently has been transferred to a modern office building on the same site.