They are cutting up a tonne of cabbage this week in Alba Iulia. Come Friday the whole lot will be cooked up with sausage in giant cauldrons and then served up gratis outside the Transylvanian city’s princely palace.

This free lunch is part of the celebrations for Romania’s national day, or, to be more precise, its Great Union public holiday.

December 1 marks the 105th anniversary of Transylvania joining Romania at the end of World War One.

And Alba Iulia was at the heart of the action. It was in this historic city that an assembly of ethnic Romanians in what was then officially Hungary voted for union.

READ MORE: Scotland tourism: What we can learn from the Texas Tourist Tax

In 1918 a new and larger Romania emerged. This included territories now in Ukraine and Moldova that were lost as Europe’s maps were redrawn in 1945.

But enough of that Great Union has survived that after the fall of Communism its anniversary was turned in to a national day with military parades, a public holiday and, for 5000 or so folk, some free cabbage and sausage.

I am sorry if this is sounding too much like Higher History revision. But I’ll admit that over the past decade or more of intense constitutional debate in Scotland I keep thinking about all the other unions in the world, such as Romania’s.

Nationalists, understandably, like to focus on the slew of new sovereign nation states that have come in to being over the last century or so.

Think of all those memes on social media with world maps showing a parade of independences.

But unionists – and I do not think this is an unfair observation – rarely talk much about all the states formed by territories joining together. Perhaps because this process is far from always voluntary.

True, those on the pro-UK side of our endless constitutional wrangling kept arguing that, despite never drawing any meaningful comparisons, our union was definitely the best.

READ MORE: We must challenge the race hate against Humza Yousaf

The Conservatives even come up with a slogan. The UK, some poor backbenchers were rolled out to repeat before and after the indyref, was “the most successful political union in the world”.

I am sure there are people who sincerely believe this, even if it is far from obvious what the slogan means.

It’s not like Norris McWhirter and Roy Castle had a list of unions that worked well on Record Breakers. Not that I remember anyway. Though I doubt anybody would doubt the brilliant if fanatical Mr McWhirter’s pro-British patriotism.

What might we mean by a successful political union? One that everybody wants to keep?

That is not entirely the case for Romania’s Great Union. There are still ethnic Hungarians in Transylvania, more than a million of them. There are a couple of counties in eastern parts of the region, nestled below the Carpathians, where they form a majority.

There are citizens in area – often called Székely Land in English – who would like autonomy, though this is prohibited by Romania’s constitution. There are also nationalists inside Hungary’s current borders who prefer old maps on which this part of the world is theirs.

READ MORE: HS2 debacle and Irish bridge fantasy shows UK can't built back better

The Great Union of Transylvania with Romania still looks pretty settled. But there is another holiday coming up in Romania: Little Union Day in January.

Now I have no idea how to rank political mergers by their success but this one has got to be up there.

Back in 1859 the principalities of Wallachia and Moldavia united under a single ruler.

A French-educated former revolutionary and lawyer named Alexandru Ioan Cuza was “elected” prince – or maybe “selected” is the better word – by tiny local elites in what back then were still vassal states of the Ottoman Empire.

Cuza embarked on a series of state-building reforms in Romania – as the united provinces gradually came to be recognised.

He had the authoritarian style – and facial hair of France’s Napoleon III – and ended up being escorted in to exile by that was called a “monstrous coalition” of conservatives and liberals who set aside their differences to turf him out.

Cuza must surely, though, rank as a great European “unionist”. His Little Union – despite early opposition from “separatists” – has to be one of the most successful of its kind. You may well have read stories about Hungarian irredentists or autonomists in Transylvania. But trouble between Wallachia and Moldavia? Not so much.

But there is a twist. Cuza was also preparing his nation for independence. He was a unionist who, in Scottish terms, was also a nationalist.

Romania, under his successor, a German prince, finally achieved fully recognised independence from Turkey in 1877.

This, apart from anything else, reminds us that the labels we give to our rival political tribes far from always apply well to other countries.

Romania gets three parties. Two for its unions – on December 1 and January 24 – and one for its independence Day. Mind you, the latter does not come with a day off.

It is curious that the UK does not mark its founding unions. Is that because the legacy of these great events remain politically contested, fraught with identity politics and competing interests?

To be fair, January 1 and May 1 – the anniversaries of the creation of the United Kingdom in 1801 and Great Britain in 1707 – are usually already days off.

Me? I think that if the British union was the most successful in the world we would be having parties to celebrate it, just as in Romania. So where are our free cabbage and sausages?

The Great Union is not just celebrated in Romania. There will be people in modern largely Romanian-speaking Moldova, handed to the USSR at the end of World War One, who will mark the day too.

Such unionists – unioniști – have a long way to go and lots of obstacles to overcome, including a frozen conflict in breakaway Russia-backed Transdniestria.

Anyway, have a lovely Great Union day when it comes.