Finally, even if this particular letter is "not historical", we do have other, substantiated letters from the Zaporozhians to the Ottomans with various insults, and the painting was created with the help of historians, so the painting is fairly accurate even if the exact letter may have been a slight exaggeration of other contemporary letters.

There's no doubt that they did that. We have multiple documented responses, some of which are quite witty I'll add. (If you remove the old-fashioned tone of voice from the translations and speak them as someone would today, even the drier ones can be fairly amusing.)

There are also embellished or fabricated responses even in modern times.

The question is - which of those is this letter? I don't think we can rule out any possibility based on the information we have available. We simply have a gap of a hundred-odd years in which we can find no surviving written evidence that people talked about it. I don't think that's evidence enough that it didn't exist.

I think that's almost wholly because of the the "thou", which was added to distinguish from the polite plural "you", but maybe it shouldn't have been. I doubt anyone would have mistaken "fuck your mother" for the polite plural.

Agreed. There's a lot of unwarranted skepticism by both real, and wannabe history experts these days. Even events from last century that were heavily documented in books and scholarly texts are sometimes called fake by people on the internet because there isn't a web link to the material.

It makes me sad when I see the library throwing out reference books, knowing that most of that information will be gone forever, and the people who know its contents will never be believed.

Edit: misread context- kneejerk Ukrainian > Russian correction. Although I’d still want it clear that this is Ukrainian history more than Russian.

It's definitely a fair to name that Ukrainian history from your perspective. It's a also fair to name that Russian history.

A lot of people could argue that is specifically Cossack history, because Cossacks could be viewed as separate ethnicity with their own history.

Somebody will say that's Russian word is correct, because "Russian" is umbrella term for both velikorossy (Great Russians) and malorossy (Ukrainians) :-)

But it's definitely fair from modern Russian perspective and from modern Ukrainian perspective to claim this history as their own.

In truth, the Zaporozhian Cossacks were their own people, to classify them as strictly Russian or Ukrainian somewhat erases their culture and history.

You're absolutely correct that the Zaporozhians were somewhat of their own people, much like the Don and other groups of Cossacks - which can be seen in them uprising against the Polish-Lithuanian rulers and the Czar respectively and trying to form their own states. I wouldn't go so for as to say that they aren't part of Russian-Ukrainian history either, just that claiming for them to be the same as modern Ukrainians or modern Russians makes as much sense as modern Greeks claiming to be direct descendants of Alexander the Great.

don't say this to either of the macedonias :)

Русь

TL;DR the letter most likely is an 18th century Russian translation/modification of a typical 17th century Polish anti-Turkish pamphlet which was taken as genuine by 19th century Ukrainian nationalists.