("In the background on the wall there is a reproduction of the painting 'Cossacks write a letter to the Sultan' by Repnin. Knowing the Russians, this is no coincidence.") (Russia sending a message)
Reply of the Zaporozhian Cossacks
Copy. Not the original.
Note - those Cossacks of the Zaporozhia, in Repnins famous painting, were Ukrainians. And free men.
There were other Cossack hordes later and further and further east, but those were all in service to the Tsar, unlike those original guys on the Dneipr, free from all masters, Tsar or King or Sultan.