Certainly "a" capitol of the world (one among many capitols of the world, depending upon what kind of a deserved or undeserved "capital" you are looking for in the world). London has always felt more superior to itself than to its European or global equals. But confronted by global economies, resources far greater than London's (UK's), there is no way it can save its " world capitol-ness" or uniqueness except by compromise and forging mutual concessions with other great capitols,  countries. Brexit, for example, isn't going to usher into the world any kind of "new age," as it were, or new Victorian epoch, empire and all (or even Elizabethan Age), with King Charles and his queen, Camilla, on the throne. UK is empire-less and, at home, at least, in great need of keeping itself together (with Scotland and Northern Ireland quite upset with the vote to exit from the EU). Even 96% of the citizenry of Gibraltar voted to stay in the EU. London has to deal with that angry dot of Europe, too.