Many thanks for the grid Prim. I may have got lucky because I didn't hit any red herrings doing it. Only issue is, strictly speaking, London doesn't fit the description. :-)

The Linear group is a new one on me. Still, fair enough. Good one. Not sure why you think London doesn't count, Angie...?

Hi Voidy. London is the capital of England. England isn’t an island state or whatever the term was. Great Britain (England, Scotland & Wales) doesn’t have a capital.

London is capital of the British Isles

Really angua?
Have you tried explaining that to the people of Dublin? It won’t go well.
The British Isles (5 countries) doesn’t have a capital.
The UK (4 countries) ditto.
Great Britain or Britain (3 countries) ditto.
England has London.
Scotland has Edinburgh.
Wales has Cardiff.
Northern Ireland or The North of Ireland or The 6 Counties or Ulster has Belfast.
The Republic of Ireland has Dublin.

Hey Angie, thanks for the exhaustive answer. I thought London was the capital of the UK, but it seems that while it is commonly perceived as such, it holds no *official* status thereas. I learned something, yay!
But England's a country on the island of Britain, (I think "island nation" was the term?) so... hmmmm.... that wouldn't work with Richard Osman's standard definition on Pointless.
Okay, I no longer have a firm opinion on this! :-)

Meanwhile, the phrase "British Isles" should be used very carefully in Dublin. :-)

All of you put your shoes on and go out somewhere...!

We would do, but until we establish where we are, it’s dangerous.