I think the above commenter's point is that "countries" doesn't just mean the formal nation state, but the cultural group. The nation of China was created on 1949. China is much older than 75 years. Likewise, Germanic tribes existed as far back as the Ancient World.

I don't think anyone claims it's /exactly/ the same entity (except in a legal sense after a government-in-exile is restored home, such as after World War II). But there's a general sense that a country can in some way be a continuation of a previous one, particularly if it shares the same language and a similar territory.

Compare the borders of something like the Duchy of Bohemia and the modern-day Czech Republic. That's two states over a thousand years apart, separated by centuries of highs and lows, including uncountable foreign invasions and Austrian rule for four centuries. And yet there's something obviously parallel to them - states ruled from Prague, inhabited largely by Czech speakers, extending to virtually the same territory.

Europe's natural and linguistic borders are relatively stable, so the emergence of similar states over similar territories in time is not unexpected.

Before the european revolutions in the 19th century, the notion of a national state didn't really exist.

It was more about who controls what. Doesn't mean the actual population of the controlled areas changed much.

To give an example from my country's history, Romania has been divided into 3 provinces until very recent (historically speaking) times.

The first unification happened in 1600 when Michael the Brave, the king of the southernmost province, managed to take control of all 3 for about a year. He didn't proclaim himself king of Romania, he called himself king of Wallachia, Moldavia, and Transylvania.

100-150 years earlier, Stephen the Great, the king of Moldavia hit Wallachia militarily several times during his reign... not to conquer it and unify but to place a king friendly to him on the throne.

Pretty sure you can find examples like this in any country's history. Germany and Italy for sure, since they've been divided politically into smaller provinces for a thousand years.

Poland was occupied by Germany during WWII. The people still considered themselves Poles during this time, and the only reason there wasn't a 'Poland' was because of military strength, so it seems silly to say that early 1939 Poland and late 1944 Poland are different countries because of lack of continuity. Certainly, almost all Poles will tell you the country 'began' (it kind of had a soft start) in 966, and not in 1944.

(Note: there was technically the government-in-exile in London, which you could argue maintained continuity, but I don't think it's necessary so I'm leaving that out of this.)

I can speak of Poland which had a discontinuity of 123 years. For most practical purposes Poland 1918 was not Poland 1795. It had none of the military alliances nor administrative obligations, just a new country out of nothing.

The only continuity was in the collective mind of people who identified as Polish and grabbed the opportunity to fight and (re-)establish their own country.

Now if you look at the continuity of ideas, it gets pretty philosophical so we could leave it to philosophers... if it wasn't for the fact that people use the ideas to justify wars. I don't have a confident answer for continuity between "being Polish in 1795" and "being Polish in 1918".

Was Iceland a country when it was founded? Or later, with the start of the Icelandic Commonwealth? Did it end being a country after the pledge of fealty to the Norwegian king in 1262?

If it was always a country, then go west. When Eric the Red founded Greenland, was it a European country? Did it become a country? After the Norse died, the Danish-Norwegians still claimed sovereignty, and reestablished a colony. The place is now a constituent country of the Kingdom of Denmark.

Some examples were given as answers, occupations etc. But even when nothing like that happens, in the "continuous" case - a country is still undergoing changes. Laws, language, culture, people, etc are not the same 100s of years later. So even that is kind of a Ship of Theseus type of challenge...

I think non-continuous succession of the same entity comes down to using or grandfathering the law, claiming the same assets, but also honoring liabilities of the predecessor. It's the same as with companies.

Mostly through people still living in the same place remembering the glory days of old. If you look at Poland and Lithuania, which became Poland-Lithuania, which roughly split so that Poland went into Prussia and Lithuania into Russia; where Prussia lasted for 100 years and ended with WW1 where Poland re-emerged and had their common sense of identity enhanced by Hitler almost immediately re-invading, and Lithuania existing as part of the USSR for some additional 100 years before breaking out and doing their own thing.

There's still a cultural identity in these places. The people living in them weren't replaced or relocated, primarily the flag and regent.

> What does it mean for a country to exist non-continuously?

What does "country" means? State? Geography? Leadership? Ancestry? People?

If you get far back enough the birth of France starts with Gaul which bears more than a passing resemblance with today's France:

https://i5.walmartimages.com/asr/3044d40d-8af2-47aa-81e5-785...

And around 50BC with Vercingétorix surrendering to the Romans at Alésia the tide turns and it gets administratively split up largely to ensure they don't come together as a force against the Roman Empire again. Then as the Roman Empire starts showing cracks, various local powers emerge again:

https://www.alex-bernardini.fr/histoire/images/division-gaul...

Then "France" itself starts to exist since Clovis I united Franks in 481 and around 511 looks somewhat the same as today again if you squint hard enough:

https://i.pinimg.com/736x/fb/3b/79/fb3b7985c2063f6a9839c6918...

But then in 840 it gets split in three after infighting among Charlemagne grandchildren, tearing the whole thing apart again:

https://www.lhistoire.fr/sites/lhistoire.fr/files/img_portfo...

Middle one's fate is to dwindle, west one will become France, right one will become Germany.

France's shape will then vary a lot through time, alliances, weddings, and battles, sometimes eaten at on the east, west, north, south, but more or less gravitating around the center part.

But then here comes Prussia in 1870, then WW1, then WW2, culminating in the partial occupation then administration of northern and western France between 1940-42 and a literal fork of France leadership and government: France de Vichy led by Pétain in the south east, France Libre led by De Gaulle exiled in London. In theory the Vichy government was also leading occupied the north of France but in practice it was ruled by Germany.

1942 comes and Germany resolves the conundrum by forcefully merging south with north, France de Vichy becomes devoid of any power (not that it had much before, being a satellite state of Germany), France is de facto a part of Germany, essentially leaving only France Libre as an actual French government, which is not even in any part of the territory!

So again, what does "country" means? State? Geography? Leadership? Ancestry? People? There's definitely some ship of Theseus going on along these 2k years, as well as forks, takeovers, infighting, and whatnot. This abridged version only highlights so much as there's much more intricacy to it, reality is incredibly messy, yet somehow "France" going all the way back to Gaul over 2k years carries some sense.