Hello!. This is the time for the emperor, Napoleon Bonaparte The Emperor. And this was one of the several tryings for the constitution of the whole Europe under only one leader. After him would arrive others as the British and unfortunately, and partially, Hitler...But this is another tragic history (the shame of Europe).
As Spaniard, I would tell you that we celebrate when we recovered our country against Napoleon with what we call "The Independence War" (1808-1814) and it's celebrated each 2nd of may every year. From this date we wrote and approved our first Constitution, the "PEPA" in Cádiz City (called as "Constitution Of Cadiz" too).
It's told that Napoleon said , in his retire island of Elba that "all his nigthmares and problems started from his lost in the Independence War Of Spain". The Russian front and other little problems which became too big to fight against for made his empire collapse.