Why was Louis Auguste excuted?

Answer 1

There have been several people with that name, but you are perhaps thinking of the husband of Marie Antoinette, who was executed, along with a lot of other people, during the French Revolution. At that time the French nobility were being executed just to overthrow the aristocracy, and not necessarily because of anything in particular that a given individual did. It was a kind of revenge killing that the lower classes did because they resented having been made into a lower class, and wished to assert their equality in the most emphatic way they could.