The first English version of his romantic novella Clisson et Eugénie, is due out this autumn, according to the Bookseller magazine.

When Napoleon died in exile on St Helena, aged 51, his possessions included the manuscript of his novella, the pages of which were scattered as souvenirs. But the fragments have been pieced together over the years, with the first page fetching £17,000 at auction two years ago.

The manuscript was written when he was an ambitious young soldier aged 26, shortly before he made his name by smashing a royalist coup in Paris in 1795. It tells the story of a brilliant young soldier who loves, loses and dies heroically in battle "pierce by a thousand blows."

Inspiration for the novel was the general's love affair with Bernardine Eugénie Désirée Clary, whose sister married his brother Joseph.

The reconstruction was published last year in French, and in October will be released in English, translated by Peter Hicks and Emily Barthet, along with an essay on Napoleon by the author and psychiatrist Armand Cabasson.

In one extract the soldier's beloved Eugénie writes: "I am worried and unhappy. I feel numb. Come to me without delay. Only the sight of you will cure me. Last night I dreamt you were on your deathbed. The life had gone out of your beautiful eyes, your mouth was lifeless, you had lost all your colour. I threw myself on your body: it was icy cold. I wanted to bring you back to life with my breath, to bring you warmth and life. But you could no longer hear me. You no longer knew me."

Jane Aitken, director of Gallic, the book's publisher, said the book will show Napoleon to be "an accomplished writer of fiction".

"Although the piece of writing is short, it does cast an extraordinary light on Napoleon, who is someone we all think we know. We in Britain think of him as a military man, but here we see the romantic side to him."