A newly-published letter written from the body-strewn battlefield at Waterloo highlights the courage of soldiers in the face of “the most bloody” of conflicts, experts have claimed.

Written by British soldier Captain William Turnor, the handwritten 200-year-old note describes the battle in breathless prose – which has never before been published in full.

He claims the British infantry – led by the Duke of Wellington – ‘immortalised itself’ on June 18 1815, and speaks of the end of Napoleon’s reign as Emperor of the French.

The newly published letter written by Captain William Turnor from the body-strewn battlefield at Waterloo. Photo: Cambridge University Library/PA Wire

It is among a series of documents set to go on display at Cambridge University Library from tomorrow as part of an exhibition looking at how Waterloo was written about in the immediate aftermath.

Exhibition co-curator John Wells said: “Waterloo is the most famous battle in modern European history, and from the very first moment soldiers and civilians alike wanted to put their experiences and emotions into words.”

Capt. Turnor, born in Esham, Hampshire, was aged 33 at the time of the battle and served with infantry regiment 14th Foot.

He went on to become a major general, also serving in India, before dying in 1860 aged 78.

Written the day after the battle, the letter describes the exhilaration, confusion and savagery of what he describes as “the most bloody as well as the most decisive battle”.

Describing how the battle was fought against the backdrop of continuous heavy gunfire, he adds: “The cannonade was horrendous on both sides.

“The French fought with desperation and I am fully convinced that no troops on earth except the English could have won the victory, they are in action savagely courageous.

“The cavalry of the enemy particularly distinguished themselves and charged our infantry when in squares of battalions, four, five, six times, but they were not to be broken. Our infantry has immortalised itself and its conduct has never been surpassed, indeed never equalled.”

Capt. Turnor went on to explain how troops had marched on the 19th, before he had finished the letter, forcing him to conclude it four days later. After that period of reflection, he writes: “The only friends of Buonaparte are his soldiers and they are now deserting him: his army is quite dispersed.”

He also takes time to apologise for his hurried handwriting: “You will I am sure excuse this vile scrawl. Tidy is as well as a man can be who sleeps on the wet ground.”

Other exhibits in A Damned Serious Business: Waterloo 1815, The Battle and Its Books included a book from Napoleon’s personal library while in exile and an invasion map of the UK.

The exhibition runs until September 16.