France had been united for almost 300 years before Napoleon had any power. Maybe you are thinking of Germany.
Perhaps....it’s hard to remember what consisted of “The Empire” without doing an intensive Google search or hitting my book collection....but a “united” France 300 years before Napoleon......
Henry V moved against Kingdom of Normandy, and when he was repelled by force (and dysentery) and moved up the Somme River toward eventual victory at Agincourt....and keep in mind that Agincourt was another battle in the 100 Years War.
Complex stuff, but fascinating....