Poland messed it up, they should have chased the Teutonic Knights down as they were retreating and slaughtered them all. Instead they left them to retreat to Malbork. Since they messed it up they had to deal with the Teutonic Knights for another 100 years until the Tuetonic order fell apart and reformed as Prussia but only after Poland kicked their ass again. The new "Prussia" then gave homage to the king of Poland, who should have went into the place and leveled it once and for all, but he messed up.
Two hundred years later Prussia which at one point sworn undying loyalty to Poland joined up with Austria and Russian and together the three of them partitioned up Poland between themselves. So much for undying loyalty
Overall Poland at one point was a major power in Europe, but because the gentry loved their freedom and most of the Polish kings could not form a centralized government in the face of resistance from the nobles, Poland ended up falling apart due to internal pressure and external influences.
Poland was an interesting country to read about, countless wars, real politic, Poland expanding, shrinking, disappearing from the map and then emerging again. Definitely see were Poles got their love of freedom from. Interesting place to read about, wish there were more books in English about it.
