Political subdivisions in the United Kingdom

According to older atlases, England, Scotland, Wales, and Northern Ireland were divided into a very different pattern of counties or other administrative divisions than they are now. Northern Ireland, for example, retained the old Irish counties until the 70s or so; now the administrative divisions are totally different there and elsewhere in the UK. When was this done and why?

This was done so you could ask a question about it in the wrong forum, and a mod could come and move it to the right forum for you.

That’s all I know, sorry. :slight_smile: