The almost unknown Trinitarian Order since the 13th century played an eminent role in the liberation of Christian slaves from Muslim countries. In 1688 the Order has been installed in the Austrian Habsburg Monarchy. From this base it operated very successfully in the Ottoman Empire, the Black Sea region and Northern Africa. In this study, this humanitarian activity is discussed in its religious, political, cultural and social contexts. The Austrian Trinitarians from 1690 to 1783 helped nearly 4000 captives of war and other distracted persons to return to their home countries. For the order itself, the "salvation of the souls" was the main target in that. The documents preserved also contain information on the redeemed persons and on the phenomenon of slavery as a whole in the Mediterranean region.