How about forming the former Roman Empire using the Holy Roman Empire?
And not the Electors, but one of the weaker member states. The Electors (Bohemia, Austria, etc) are usually pretty good.
After you've formed the HRE, take on the North Italians then the French. Move down into Iberia and take it via naval and land. I'm pretty sure the Spaniards have a decent military concerning navy around..1400s.
After you are finished with the west, take the rest of Italy to make sure your eastern campaigns mostly consist of Hungary, and the Ottomans.
With those two taken care of, the hardest goal would be to take all of North Africa.
And not the Electors, but one of the weaker member states. The Electors (Bohemia, Austria, etc) are usually pretty good.
After you've formed the HRE, take on the North Italians then the French. Move down into Iberia and take it via naval and land. I'm pretty sure the Spaniards have a decent military concerning navy around..1400s.
After you are finished with the west, take the rest of Italy to make sure your eastern campaigns mostly consist of Hungary, and the Ottomans.
With those two taken care of, the hardest goal would be to take all of North Africa.