The King of Navarra was originally the King of Navarra and of Basque culture... however, he was also a member of House de Normandie, who were nearly wiped out following a failed invasion by William. William was very briefly King of England before Harald tossed him out, who in turn lost it back to the Godwins. In the late 1200s, de Normandie finally reclaimed England. Since then, though, there House has spread out elsewhere, including the Basque branch that become Kings of Navarra (and Aragon). Awesomely, he just inherited England when the last of the line up there died out.
Still, I was impressed to see it. The English Isles have been insane this game. Scotland is ruled by the Saxon Dunbars and have become Kings of Norway and Finland through inheritance and crusades respectively, and now England (and before it, Brittany) are under the control of Navarra, who has managed to survive.
France is being its usual obnoxious self. I plan to convert this one to EUIII (IV? hehe) eventually, so I have some serious editing to do in order to stop the French from being the BBB right at the start.
Also of note: Portugal was formed by a side branch of House Ylving.