And as a Scot I should point out that Scotland is about a century older at 843 AD - but then neither have really existed as separate countries for centuries. ;-)
They establish continuous occupation by the same bloodlines, I asked what the definion of country is - there's oral history and law going back along with the paintings.
Bear in mind passports are only relatively recent objects.
Also worth pointing out the British tried that "I think you need something more" line with Terra Nullius .. and their own legal system ditched that as rubbish:
remained sovereign for tens of thousands of years.
Whereas, for example, the "United Kingdom" as a country (of four kingdoms) only dates back to 1801, prior to which there was a long history of contested sovereignty claims, there's some interesting paperwork declaring a King of Scotland as a the King of England, etc.
1066 was just another guy coming to claim the throne. You wouldn't say a company was abolished when it gets a new CEO, and you shouldn't say a country is no more when someone claims the throne.
to visit, absolutely. But you don't see the Americans insisting on getting their own ceremonial King as head of state in name only. They prefer to love that stuff at a visiting distance. This is also why "Downton Abbey" etc does so well in the USA.
I'm a Brit and didn't realise until recently that England is one of the world's oldest countries (927 AD).