How far into Russia do I have to go?
Nonsense, there is no use of the term Britain in RFC, only England. You have to control England's core area (the area that flips to England after they spawn) when playing for the German UHV.'Control England' is a little ambiguous since Inverness is Scotland, not England, so you shouldn't have to control that city.
Ireland is excluded from the English requirement for the Germany UHV condition, as is clearly shown in the Atlas.Or Ireland for that matter.
It means that you have to control more cities than the civ whose core area you are invading. A common trick is to collapse the civ, and keep only 1 city. If another civ takes the cities, it doesn't matter.
For example, if you conquer France, and keep Paris. And then Spain takes the other cities, you still fufill the conditions.
You could even use the RFC Atlas to find the answer.
Culture? Don't you know that Germans are supposed to be bloodthirsty militarists?
And you've stolen my signature (which I in turn stole from Terry Pratchett, so I'll better be quiet now ).
And you destroyed the Buddha reference. More accurate, less funny. Pratchett knows what he's doing.