The German Catholic military order of the Teutonic Knights settled in the Baltic area in the early 1400s in a bid to spread Christianity among the pagan tribes in the region, and to Poland and Lithuania beyond. To defend their lands from Catholic colonisation, the Slavs, the Poles and the Lithuanians signed a treaty. On 15 July 1410 the allies defeated the Tuetonic Knights in a fierce battle at Grunewald in Poland.

Mucha chose to depict the scene of the battle the following morning. The Polish king Wladyslaw stands in the middle of the body-strewn battlefield and covers his face in horror. His country may be free, but this freedom has come at some cost.