Gw mau tau Silsilah dari Konrad I dari Masovia

Catholic Encyclopedia Innocent III resolved (1207) to organize a new crusade...Instead of concentrating the forces of Christendom against the Mohammedans, the pope himself disbanded them by proclaiming (1209) a crusade against the Albigenses in the south of France, and against the Almohades of Spain (1213), the pagans of Prussia, and John Lackland of England.

Konrad of Masovia sent Polish crusaders against Prussian after 1209