Here's what I used in my campaign world (link in the sig)
British Isles - Britannia
- Ireland - Hybernia
- Wales - Cymru
- Scotland - Kingdom of Caladonia & Caladonian Highlands
- Britain - Albion
France - Galia
Of course in my campaign world France is not a united kingdom and is broken up into 6 regions; Aquitaine & Gascony, Breton & Armorica, Burgundy, Flanders & Hainaut, the Holy See (Avignon) and France.
Spain - Iberia
Like France, the Iberian pennisula has not been united under one king yet, thus the following kingdoms exist; Aragon, Castile & Leon, Navarre, Portugal and Granada
Central Europe - Central Eurpoa includes The Empire (fromerly the Holy Roman Empire), Bavaria & Ostland, Bohemia & Moravia, The Cantons, and Holtwould & The Wuldgraftdums
Italy - Italia & Roman Republic
Northern Europe - Northern Europa is made up of Danmark, Isaland, Kalvala, Karelia, Lapland, Norge and Sverge
Russia - Principalities of Rus
Africa -
Japan -
China -
India -
Arabia - Most of Mediterranian Africa is included in our Arabia (based on it's religious affiliation). The whole is known as the Levant (I know not entirely accurate). I kept the original names, though a lot of old empires didn't go away (i.e. Mesopotamia, Arabia, Persia, Kingdom of Antioch and the Ottoman Empire are all alive and well)