hegemony

What's the best time and nation-state to create a long-lasting hegemony over a majority of Europe? Preferably this would also include the integration of the conquered territories as well. France comes to mind due to the disparity of population between France and the surrounding nations.

Challange: Make France the strongest nation in europe with a pod in 1917.

So i read that Charles V was very close at creating a so called "universal monarchy" as HRE in the early 16th century. What would that even mean if it was fullfilled? Would the reichstag cease to exist? Would there be a true standing army for the emperor to use? Where would be the capital? What...