Book excerpt: This is the first full English translation of Marino Sanudo Torsello's Secreta fidelium Crucis, a piece of crusading propaganda following the fall of Acre in 1291, written between 1300 and 1321 and based on the translation edited by Jacques Bongars in 1611. With references to 13th-century Mediterranean history, especially Louis IX of France and Charles of Anjou, it contains a vast amount of cartographical, ethnographical, geographical and nautical information, with unique insights into events and personalities not only in Outremer, but in Western Europe.