ABSTRACT
The participation of various military orders in the initial phase of the Prussian crusade, before it was dominated by the Teutonic Knights, has been the subject of research conducted by, among others, R. Frydrychowicz, W. Polkowska-Markowska, H. Lowmianski, W. Kuhn, G. Labuda, T. Manteuffel, S. M. Szacherska, Z. H. Nowak and J. Powierski. The recognition of armed expeditions against the Prussians and Sudovians as crusades brought about the inclusion of the military orders within these expeditions. The military orders had a role to play also in the plans of the dukes who took over the initiative in the Prussian campaign in the 1220s, especially after the defence system of the Mazovian-Prussian frontier based on lay knighthood collapsed in 1225. Participation in the Prussian Crusades was thus a form of adaptation that, with the exception of the Teutonic Knights, was imposed upon the military orders by the rulers, and not one that they followed voluntarily.
