Not at all! [He's a chatty fellow, after all.] While there has been a change of policy within the empire, Britannia used to control quite a bit of land. It still holds eminence over the North and South Americas, but has given up it's more recent Areas. Japan, for instance.

I can only imagine the other Areas are next.

Though that's all recent! I'm sure you're more interested in what led to Britannia leaving Europe at all. The simplest explanation is that the French won. Bonaparte conquered the original Isles and ousted the nobility, which then fled across the ocean.