The UK is one kingdom (not several) but it's composed of several countries: England, Scotland, Wales and Northern Ireland, plus dependencies and overseas territories (islands).
There's a British parliament that represents them all, but Scotland, Wales and Northern Ireland have their own regional bodies. England does not have a parliament, because England represents such a high percentage of the UK's population the British parliament kind of represents England anyway (though polls show that most English people would like to have an English parliament).
I don't know much about the Commonwealth, but it's some sort of agreement beween countries that used to belong to the British empire. It has little practical purpose as far as I know.
No troll is too much for me to handle. I rehabilitate trolls, I train people. I am the Troll Whisperer.
