An unknown poem by Percy Bysshe Shelley has been discovered nearly 200 years after it was written.
Shelley's pamphlet was written under a pseudonym
The 172-line poem was included in Shelley's pamphlet Poetical Essay on the Existing State of Things, which was printed in Oxford in 1811.
The political work was never published again and its existence has been doubted by some until now.
The poem, which carries an anti-war message, is up for sale by antiquarian bookseller Bernard Quaritch Ltd.
Shelley published the 18-page pamphlet under the anonymous pseudonym of "a Gentleman of the University of Oxford".
Richard Linenthal, a director of the bookseller, said it was "a discovery one dreams of making".
Mr Linenthal said the book had been brought to Bernard Quaritch Ltd for verification by another bookseller who had found it and discovered it was Shelley's work by doing internet search.
"He read the title... typed it into Google and found a discussion on Shelley's long-lost books," he said.
Mr Linenthal said he expected the future buyer to publish the work and "hoped it would remain in this country".
Bernard Quaritch Ltd will now enter into discussions with potential buyers.
"We cannot comment on its commercial value," said Mr Linenthal.
Shelley's essay was originally published to raise money for radical Irish journalist Peter Finnerty who was in prison for libel after criticising Ireland's then Chief Secretary, Lord Castlereagh.
Shelley also attacks Lord Castlereagh in his poem, describing him as one of the "cold advisers of yet colder kings", who, as the British Secretary for War and the Colonies, "sent English soldiers to die in Low Countries".
Napoleon is described as "a meteor on the midnight blast".
Shelley, who was expelled from Oxford in 1811 following the publication of another pamphlet, The Necessity of Atheism, eventually settled in Italy.
His most famous poems include Prometheus Unbound, To A Skylark and Adonais, written in memory of Keats.
His second wife Mary wrote the novel Frankenstein.
Shelley drowned while sailing in the Bay of Spezia, near Lerici on the Italian Riviera.