[Symbiote]

The three kingdoms which are united are the Kingdom of England, Scotland and Ireland, the first two by the Acts of Union 1707 [1], and Ireland added by the Acts of Union 1800 [2].

Wales is part of the Kingdom of England, under the "Laws in Wales Acts 1535 and 1542" [3].

Without Scotland, it becomes the United Kingdom of England and Northern Ireland, leaving the Kingdom of Scotland. Scotland would be assigned an ISO 3166 code. SC, SO, ST, SL, SA, SN and SD are all taken. Perhaps they can have "AB" for "Alba". The "GB" code would be unassigned.

Without Ireland, it becomes the United Kingdom of Great Britain. Northern Ireland presumably joins the Republic of Ireland in this case.

Without both, it becomes the Kingdom of England, the Kingdom of Scotland, etc. England would then need an ISO code, "EN" is available.

[1] https://en.wikipedia.org/wiki/Acts_of_Union_1707

[2] https://en.wikipedia.org/wiki/Acts_of_Union_1800

[2] https://en.wikipedia.org/wiki/Laws_in_Wales_Acts_1535_and_15...

[m-i-l]

According to wikipedia [0] and UK government sources [1] there are 4 countries in the United Kingdom of Great Britain and Northern Ireland: England, Scotland, Wales (together forming Great Britain) and Northern Ireland. If Scotland and Northern Ireland left the UK, it is conceivable therefore that the United Kingdom would continue to exist but as the United Kingdom of England and Wales.

[0] https://en.wikipedia.org/wiki/Countries_of_the_United_Kingdo... and https://en.wikipedia.org/wiki/United_Kingdom

[1] https://webarchive.nationalarchives.gov.uk/20080909013512/ht...

[thefringthing]

Wales is a constituent country of the UK but not a kingdom.

[toyg]

The constitutional position of Wales has significantly changed with the three devolution acts introduced in the last 20 years. The Wales Act 2017 in particular made the assembly/parliament permanent and Welsh law as a separate body; that means Wales is effectively its own country in the UK, on par with the other three.

[osullivj]

The 1707 Union created the Kingdom of Great Britain. 1801 created United Kingdom of Great Britain and Ireland. The creation of the Irish Free State in 1922 gave us the United Kingdom of Great Britain and Northern Ireland. So if Scotland leaves, the Kingdom of Great Britain ceases to exist. "Britain" ceases to exists as a political/national state. IMHO any reconfigured UK after that is an absurdity.

[necovek]

Are you implying that European Union shouldn't be called that because it does not include all of Europe's countries?

I assume no, so perhaps it's ok for a Kingdom of Great Britain not to include all of it :)

FWIW, Serbia almost kept with the Yugoslavia for as long as it had someone to unite with. It did turn into Serbia and Montenegro in 2003, before ultimately splitting in 2006.

It even got a first case of ISO country code reuse with CS (hi Czechoslovakia), but I don't think there was ever a TLD .cs for it.