The book contains several essays by Polish and German historians and art historians from the Nicolaus Copernicus University in Toruń, translated into English and dedicated to the presentation of the territorial authority of the Teutonic Order in Prussia and Livonia. The authors focus on issues concerning the organization and internal structure of the territorial authority, formation of political borders, administrative divisions, defensive architecture, urbanisation of the country and church structure and divisions. The book includes a list of officials of the Order in Prussia and Livonia prepared by German researchers. Authors: Marian Arszyński, Marian Biskup, Roman Czaja, Benrhart Jähnig, Klaus Militzer, Zenon Hubert Nowak, Andrzej Radzimiński, Janusz Tandecki.