Napoleon Bonaparte's account of his victory at the Battle of Austerlitz, dictated during his exile on the island of Saint Helena, went on sale Wednesday in Paris for one million euros ($1.2 million).

The account of the 1805 "three-emperors clash" with Russo-Austrian forces, which is considered Napoleon's greatest military triumph, takes readers through preparations for battle and the fighting itself, completed by a plan drawn by his loyal aide-de-camp General Henri-Gatien Bertrand on tracing paper.

Napoleon does not refer to himself in the first person, instead prefacing his remarks with 'the emperor says'
Napoleon does not refer to himself in the first person, instead prefacing his remarks with 'the emperor says' AFP / Thomas COEX

The densely packed 74-page manuscript, dictated to Bertrand, contains several corrections by the exiled emperor, who crossed out words and added remarks in the margins in tiny handwriting.

Napoleon does not refer to himself in the first person, instead prefacing his remarks with "the emperor says".

The sale comes at the start of a year marking the bicentenary of his death.

The battle is still studied in French military schools and a popular subject for re-enactments by history enthusiasts
The battle is still studied in French military schools and a popular subject for re-enactments by history enthusiasts AFP / Michal CIZEK

Gallery owner Jean-Emmanuel Raux, a collector of French imperial memorabilia, found the manuscript in a trove of documents belonging to Bertrand's heirs.

"It's the most fabulous document about French history that you could find in a private collection," he told AFP.

His daughter Alizee said their Paris gallery, Arts et Autographes, did not want to put it up for auction -- that they wanted collectors to discuss the importance of the manuscript directly with them.

The bundle comes with a battle plan drawn by Bertrand on tracing paper
The bundle comes with a battle plan drawn by Bertrand on tracing paper AFP / Thomas COEX

"We want people to come, to explain to them our passion in our gallery. We have had this manuscript for a long time. It is a great honour to have such a document in a French gallery," she told AFP.

It is being sold as part of the annual "BRAFA in the Galleries" art fair, which this year includes 126 galleries in 13 countries to the end of January, with viewings this year arranged in-person or online.

Within around nine hours on December 2, 1805, some 75,000 soldiers of Napoleon's "Grande Armee" outmanoeuvred a larger Russian-Austrian force at Austerlitz, in what was then the Austrian empire.

It helped end the coalition between Francois I of Austria and Russian Tsar Alexander I that had been financed by Britain -- and is a battle studied in French military schools to this day.

Napoleon details all the tactics he deployed to dupe his opponents into believing French forces were weak -- including earlier retreats and negotiations that disguised the fact he had already chosen the site of the battle.

His exalted account trumpets the heroism of the French, from trooper to officer, and claims even wounded soldiers hailed the emperor.

"I will lose a good number of brave men," he said on the eve of the battle. "I feel bad that they really feel like my children, and, in truth, I reproach myself sometimes over this sentiment since I fear that it will leave me unqualified for war."