I'm interested in this, but I am wondering...What would we actually role-play? Are we sticking to historical events or are those just backdrops to which we go around doing whatever we want? How much freedom do we have to do our own thing?
Just assign the actual territories of a nation in 1537 to the players when they sign up; if they want to make a new nation, make them work for it by taking over an existing nation and distorting its borders in the desired manner.
*Red glowing eyes and demon voice*