I am reading the book about a difficult history of Prussians that were conquered by Teutonic knights, partly due to the bad policies by Polish king. These brave Prussians were fighting, they organized uprisings against Teutonic knights, but they felt, although they had some local victories.
The second uprising, known in historiography as "The Great Prussian Uprising", was prompted by the 1260 Battle of Durbe, the largest defeat suffered by the Teutonic Knights in the 13th century. This uprising was the longest, largest, and most threatening to the Teutonic Order, who again were reduced to five of their strongest castles. Reinforcements for the Knights were slow to arrive, despite repeated encouragements from Pope Urban IV, and the position of the Order looked set to worsen. Luckily for the Order, the Prussians lacked unity and a common strategy and reinforcements finally reached Prussia in around 1265. One by one, Prussian clans surrendered and the uprising was ended in 1274. The later three lesser uprisings depended on foreign help and were suppressed with one or two years. The last uprising in 1295 effectively ended the Prussian Crusade and Prussia became Christian German-speaking territory, which assimilated native Prussians and a number of settlers from different German states.