/ The great mistakes of Poland's history?
The greatest mistake of us was when our cultural, political and civilizing processes turned to the East and our ancestors gave up the idea of the Latin united Europe .
Poland's culture and language would be completely non-slavic today if not for such a smart move by our slavic ancestors to stay east. After all Mieszko was only baptized after pressure.
Yes, it happened after union with the Grand Duchy of Lithuania and had (possibly still has) enormous impact on Polish mentality, our way of thinking and acting - it's why Poles are more like Ukrainians and not like Germans or Czechs.
You lack Rzeczpospolita history, Polish language and culture was dominant in the commonwealth and is the reason why most Ukrainians(Ruthenians) didn't like the idea of joining + having to convert to Catholicism. Czechs republic is divided on culture and way of life by region to region, obviously lands occupied under different countries had effects on way of life.
Well ... personally I enjoy being "semi-Asiatic" but what were our long run-benefits of the Jagellons' Union ?
Why do you come off as sounding greedy? Benefits lol...Poland was culturally aware of everything during that period. Every country in the world has its downfall - Byzantine and Roman Empire, Imperial Russia as did Polish-Lithuanian Commonwealth.
Siding with Germans (Teutonic Order) against pagan Lithuanian and Orthodox Russins would have been by far more profitable than any aliance with Lithuanians, Ukrainians or Belorussia (whatever it meant 600 years ago).
If not the Union, Poland would be today more like rich Germany or the Netherlands on the contrary to the poor European East.
It was all because of pressure from the church, in reality Poles didn't care for Lithuanian Pagans as Paganism in Poland was still being practiced. The profits at that time would have been land and so what Poland had a war with Teutonic order soon after. Slavs and Balts have had to be always close with each other suffering from invasion from all angles for example - Huns, Turks, Mongols, Swedes.