The Baltic tribes were the last pagans of Europe and both the Pope and the Holy Roman Empire were interested in baptizing them. However, this process was not peaceful and two knightly orders were tasked with bringing the new faith to the Baltics - Teutonic and Livonian. Their activity, that would be later known as the Northern Crusades, led to a number of wars with the Kingdom of Poland and the Great Duchy of Lithuania. Eventually, these states entered a union. The ensuing war between the Polish-Lithuanian alliance and the Teutonic Order culminated in the battle of Grunwald in 1410.
