Victoria Leggett As he waited for one of the greatest naval battles in British history to begin, the fighting spirit of Horatio Nelson was very much in evidence as he willed the wind to change direction and bring his enemy out to fight.

Victoria Leggett

As he waited for one of the greatest naval battles in British history to begin, the fighting spirit of Horatio Nelson was very much in evidence as he willed the wind to change direction and bring his enemy out to fight.

But just four days after he penned the words in a letter to Rear Admiral John Knight, Norfolk's most famous son died in the ferocious Battle of Trafalgar.

Tomorrow, the slightly-smudged and never-before-published note, written as he sat aboard HMS Victory, is due to be sold and could fetch up to �12,000.

Born in Burnham Thorpe, near Wells, and educated in North Walsham and Norwich, the Vice Admiral is one of Norfolk's most celebrated sons.

The two pages of his handwritten musings are likely to be the most valuable of a number of letters by Lord Nelson up for auction at Sotheby's in London.

Clearly written at the top of the page is the date - October 17, 1805 - which marked such a turning point in his life.

Gabriel Heaton, Sotheby's manuscript specialist, said: “It all began to unfold within a few hours of him writing this letter.

“The following evening the French commander began to fly the signal for his ships to un-moor. Within three days we have this most ferocious battle and Nelson dies.”

But, in keeping with his known confidence and zest for battle and not knowing what fate had in store for him, Lord Nelson was keen to get going.

In the letter he told Admiral Knight he was “anxious for an easterly wind” which would encourage the Franco-Spanish fleet to leave harbour and commence battle.

Dr Heaton said: “To be honest, Nelson's fighting spirit is never something lacking in his letters. His self belief and his belief in his men is always something that comes through strongly.”

The manuscript specialist said Lord Nelson's choice of recipient also made the letter all the more poignant.

He said: “He was in charge of Gibraltar, the nearest friendly port to Trafalgar. It was to Gibraltar where Nelson's body was taken after the battle, so Rear Admiral Knight would have received his body. It's very evocative that it was written to this man at this particular time.”

The 205-year-old letter, which remains in good condition for its age, also contains many practical comments about the preparations for battle Lord Nelson, who had already lost an arm and the sight in one eye during earlier conflicts, had made.

Describing the ships in his command, he writes of his plans to send some to Gibraltar to have sails repaired. As he tells how low the fleet is getting on drinking water, he urges: “But this keep to yourself or we shall see it in an English newspaper.”

The Sotheby's specialist said this information was key to the battle. The French commander became aware of Nelson's decision to send some ships away and it gave him the perfect opportunity to attack while the fleet was smaller and, therefore, weaker.

In the end, however, it did not matter and Lord Nelson was given news of the British victory - which destroyed Napoleon's hopes of invading England - shortly before he died from wounds sustained in the fight.

On Thursday, the letter, which comes from a private collection, is expected to fetch between �9,000 and �12,000.

That is more than double the estimates put on any of the other four letters and a document signed by Lord Nelson which will also come up during the English Literature, History, Children's Books and Illustrations sale.

The auction house believes it is previously unpublished, but Dr Heaton said it was the date that made this letter particularly valuable. He said: “Other letters written by him have come up for sale, but this is as close to Nelson's final victory and death as you can get. That's what makes it such a special find.”

The sale begins at 10.30am tomorrow at New Bond Street in London.