The spiritual knightly orders emerged in the 12th and 13th centuries in the context of the Crusades in the Holy Land, on the Iberian Peninsula, and in the Baltic region. As a new form of religious orders, they combined the older monastic ideals with the fight against the enemies of Christianity. Thus, they received considerable support and soon became present throughout Latin Europe. While the Knights Templar were dissolved at the beginning of the 14th century and the Iberian knightly orders were effectively secularized under the influence of rulers, particularly the Knights Hospitaller/Maltese and the Teutonic Order continue to exist today in a transformed form. The volume offers a comparative overview of the developments from the 12th century to the present.