Even before someone mentioned it on the RPGBN Google group I was intent on using my own country as a basis for my part in this world.
Whilst there is a rich history and more than enough land mass to steal I am hoping to try and cherry pick the best from the history of one particular culture....The Celts.
I'll add in a little Viking flavour as well to appeal to the masses.
Basically its a coastal/island nation where transport is done primarily by sea. Almost all towns and villages will be inaccessible by land and they will have some of the best pre-gunpowder navies in the world.