John, that’s certainly true – particularly when it comes to “ethnic/patriotic assertiveness”. There’s an entertaining discussion of this question in Anne Applebaum’s wonderful Between East and West: Across the Borderlands of Europe. In one highly amusing (if you like this sort of thing) passage, she recalls the ferocious controversies that used to roil the small, but determined, world of Polish-Lithuanian nationalist linguistic studies over the correct ‘identity’ of a number of small villages in the Vilnius/Wilno/Vilna region.
Then again, as Applebaum points out, there’s Adam Mickiewicz, Poland’s greatest poet, and Byelorussia’s too (there he’s Adam Mitzkevich). Lithuanians meanwhile note that while Adomas Mickevieius wrote his most famous work (Pan Tadeusz) in Polish, it begins with a reference to Lithuania, his “fatherland”…