"The Former Scottish Constituency of Northumbria"
The year is 2058.
It is 12 years since the Scottish Civil War ended.
Scotland finally achieved independence from England in the 2020s, but the newly founded Republic of Scotland was short-lived. Initially a handful of the northernmost islands seceded from the Republic in disputes over their level of funding and self-sufficiency. Then, old Sectarian fault-lines, political wrangles between the party power-bases of Glasgow and Edinburgh, and an ideological split over whether the new Republic should retain close ties with England or look more to Scandinavia caused an irrevocable split.
By 2046, the Republic of Scotland covered around a third of the historical country, with the capital remaining at Edinburgh, based in the old Scottish Parliament building.
New Caledonia, based around Glasgow, was the other major nation to emerge. The islands and very North had formed a loosely affiliated 'Federation of Scottish Islands and Highlands', but it was in the south of the old Scotland that the most controversial new territory emerged.
Occupying a space roughly equivalent to the old Scottish parliament constituency of Roxburgh and Berwickshire, a small independent nation emerged which stunned the English by declaring its constitutional name to be the "Republic of Northumbria". The English Parliament resolutely refused to recognise the new nation state, which it said was appropriating the name of a historical region of North-East England.
Undeterred by the protests of the English, the new Republic of Northumbria began to establish diplomatic relationships with the other countries that now made up the region of Scotland, and was recognised by ENAU member states including the Republic of Ireland. The country joined the UN, but, with their considerable influence as a former permanent member of the UN Security Council, the English were able to insist that officially the UN recognised the new nation state as "The Former Scottish Constituency of Northumbria".
Despite an official line that 'FSCoN' was making no territorial claim over North-East England, there seemed to be plenty of evidence to the contrary. The country's first flag was almost identical to that belonging to the English county of Northumberland, and after protests by the English, it was changed to a more neutral flag, which retained Northumberland's colours, but not the entire design.
School text-books were illustrated with maps that showed a historical 'Greater Northumbria' which covered territory from Edinburgh down past the Tees in England.
The new country funded an academic programme which sought to find evidence that St. Oswald had spent more time north of the border than used to be believed. St Oswald was an early convert to Christianity on the British Isles, and had been a fifth century King of Northumbria. Linguistic scholars were employed to "prove" that a common Northumbrian dialect existed throughout the whole historical region.
Despite more objections by the English, the new nation began to take its place in the sporting world, being admitted to UEFA and FIFA. Although official documents listed the nation as "The Former Scottish Constituency of Northumbria", to all intents and purposes everyone outside of the British Isles referred to the new country simply as Northumbria. When they competed in the 2056 Seattle Olympics, for example, their three letter IOC code was NTH, and despite carrying a sign that said "The Former Scottish Constituency of Northumbria", the team marched in alphabetical order alongside countries beginning with an 'N'.
The name dispute descended into some bitter tit-for-tat moves, which seemed childish and incomprehensible to those outside of the dispute. England renamed Newcastle's Airport from "Kevin Keegan Airport" to "Northumbria Airport", and there were repeated calls to officially rename Northumberland as Northumbria.
For their part, FSCoN funded a 'Northumbrian Unity Party' that stood in English local elections on a platform of uniting Northumberland with the new Republic.
As relations deteriorated further, and England persistently blocked attempts by the Republic of Northumbria to join the European and North African Union, the dispute became more bitter. The President of FSCoN began a tour of European countries claiming that the Northumbrian people in England were an oppressed minority, who the English Government refused to recognise and actively discriminated against. The English counter-claim was that whilst there were some Scottish-born nationals within Northumberland, they did not constitute an 'ethnic group', never had, and never would.
By 2058, the rest of the world had grown tired and impatient with the name dispute, and the two sides seemed to have backed themselves into corners where it seemed a compromise would never be reached. England refused to accept any name proposal that included the 'N' word, even with a geographical qualifier like "Republic of Upper Northumbria". The formerly Scottish Northumbrians meanwhile, stated that any name without the 'N' word was unacceptable, as that was their identity. It was difficult to see where any solution would come from....
(Of course, this is just a story, and it isn't meant to imply anything about the respective claims of Greece or FYROM to the historical name of 'Macedonia', or indeed anything about Scottish politics. I just wanted to have somewhere on the Internet I could point people to when they asked "What is the name dispute between Greece and Macedonia all about?")