King George III's 1803 war letter to be sold at auction
A handwritten letter in which King George III signals his intent to go to war with Napoleon is to be sold at auction.
The missive - addressed to Secretary of State Lord Hawkesbury - is dated May 14 1803, four days before Britain formally declared war on France.
In it, he describes France's conduct as "unfair to the last" - and signs it "George R".
Auctioneer Charles Ashton described it as a "defining moment of history".
The beginning of the 19th Century was a time of hostility between France and England, marked by a series of wars.
In the 215-year-old letter, to be auctioned on 10 January in Cambridge, the king wrote that he had "perused the dispatch and private letter from Lord Whitworth" - a British politician and diplomat who was then his ambassador in Paris.
"Conscious of the Evils that must be entailed on many Countries by the renewal of War," he wrote, "it seems necessary to attend alone to the best modes of repelling the violence with effect, and the attacking those objects which our present means render attainable."
The document, stained with age, is being sold by an anonymous private vendor and has a pre-sale estimate of between £500 and £1,000.
Mr Ashton said: "This letter is a defining moment of history, showing the King's intention to go to war with France and Napoleon.
He added: "Whilst relations between Britain and France had been somewhat strained since the Treaty of Amiens in March 1802, this letter marks the end of peacetime negotiations and contains the explicit instructions from the king to proceed with war."
The ensuing conflicts ended with the Battle of Waterloo in 1815.
Mr Ashton said handwritten letters by George III are rarely seen at auction, but "give us an insight into what was going through his mind at the time".
He said: "It really is a museum-worthy piece and could well end up in the Royal Archives."