A set of Samuel Beckett jotters, regarded by literary experts as one of the 20th century's finest manuscripts, is expected to sell for about €1m at auction.
Six exercise books of the Dublin writer's work on his first novel Murphy, and only seen by a handful of people, are being offered by Sotheby's in London next month.
The auctioneers said the notebooks will give a unique insight into how the Nobel laureate's mind worked.
Handwritten in Dublin and London between August 1935 and June 1936 while Beckett was undergoing psychoanalysis, the books are full of revisions, doodles and sketches of his contemporaries James Joyce and Charlie Chaplin.
Peter Selley, Sotheby's senior specialist in books and manuscripts, said the 800-page manuscript should redefine Beckett studies for years. "This is unquestionably the most important manuscript of a complete novel by a modern British or Irish writer to appear at auction for many decades," he said.
"I have known about the existence of this remarkable manuscript for a long time – as have a number of others in the rare book business and some Beckett scholars – but it has only been glimpsed, tantalisingly, by a few chosen individuals during that time.
"The notebooks contain almost infinite riches for all those – whether scholars or collectors – interested in this most profound of modern writers, who more than anyone else, perhaps, captures the essence of modern man."
The manuscript has been in private hands for decades. Sotheby's put a guide price of £800,000-£1.2m (€935,000-€1.4m) on it.
Entitled Sasha Murphy, the notebooks contain hundreds of cancellations and revisions and the text is substantially different from the published version, Murphy.
It includes at least eight cancelled versions of the famous opening sentence before Beckett settled on: "The sun shone, having no alternative, on the nothing new."
The story revolves around Murphy's attempts to find peace in the nothingness of the "little world" of the mind without intrusion from the outside world.