When it comes to sizes and dimensions, almost everything is relative. It all depends on who or what you compare yourself to. And it seems logical to think that to say of someone, in this case Napoleon, that he is tall or short, the average height of the time would be a valid reference. So, if the average height in France during the late 18th and early 19th centuries was 1.64 meters and Napoleon was 1.69 meters, why has the misconception that he was short survived to this day? -he was even a little taller than the average Englishman (1.68 meters)-. Well, because of two characters:Napoleon himself and the British cartoonist James Gillray.
In 1804 Napoleon Bonaparte created the Imperial Guard , an elite body within the Grande Armée that was initially charged with the emperor's personal security. Over time this unit became the main body in combat and a true reflection of the French military power of the time. To be part of this elite group, a series of requirements had to be met, such as having served a minimum of 8 years in the army, knowing how to read and write, having shown courage in battle... and having a minimum height of -1.78 meters for the Grenadiers. or 1.73 meters for the Hunters. So, if the group of soldiers that constantly surrounded Napoleon were significantly taller than him, it stands to reason that Napoleon seemed short.
And the other responsible was James Gillray , a British cartoonist famous for his illustrations based on social and political satire, being especially incisive with King George III and Napoleon. In two of his illustrations of him, based on Gulliver's Travels, he portrayed King George III and an insignificant Napoleon...
In another, together with Prime Minister William Pitt, he also represented a Napoleon of almost insignificant size in relation to the British diner...
Source:The Big New Little Book of Ignorance – John Lloyd and John Mitchinson