Base map of Wales - 1947

[minionofmidas]

That's a local government map. The thickest lines are the counties. I just wonder about the borough/cb vs UD/RD dichotomy.

[minionofmidas]

Using this I've done 1917 and 1950 maps. Hope there's no mistakes.

Merthyr Parliamentary Borough was divided into two constituencies: Merthyr Tydfil and Aberdare. Merthyr covered Merthyr CB, Aberdare everything else.

Sounds like that is a reference to the previous set of boundaries, which would mean those included a Merthyr Parliamentary Borough (precursor of what you'd now call a Borough Constituency) that covered additional areas.

[minionofmidas]

What are Caerphilly Higher and Miskin Higher references to?

[minionofmidas]

"Hundred"? I didn't know such things ever existed in Wales. Cantrefi, yes. Commotes as well. Though I've never known anything about what the Cantrefi of Glamorgan looked like. (Some moderate wiki walking later: They did, apparently. And are in some hazy ways related, but not identical, to earlier commotes.) In Gwynedd, of course, the RD map looked suspiciously like (though not identical to) an ancient Cantref map right down to 1974.