There are two kinds of honor guards.
The first had only an ephemeral role, on the occasion of the Emperor's visit to a city. The custom was to form a guard of honor there with the sons of wealthy families, equipped at their own expense with more or less fanciful uniforms. But Napoleon had also thought of constituting a troop that would go into the fire.
In 1806, he formed five companies of orderly gendarmes, equipping themselves at their own expense to perform guard duty around him in the palaces as well as in the camps. But the old guard took a very dim view of these fortunate intruders and the companies were dissolved at the end of the Polish campaign.
In 1813, the project was resumed in the form of four regiments of honor guards, in order to attract 10,000 young people from good families into the army. But the defeats hardly inclined the wealthy youth to a military vocation, who were replaced by young people without wealth, limiting themselves to providing the money for the equipment.
These four regiments, assigned to the guard, fought well during the French campaign, but also very willingly rallied to Louis XVIII, who opened up the ranks of his bodyguard to them.