Propaganda is of all times. Today social media are used. In the times of the Crusades letters and travel reports were common, which were hand copied and distributed by monks.
Reading on Jerusalem and celebrating its first Crusader conquest in 1099 was recommended, as in doing so the the glory of the event and God's help therewith would be magnified. As such this monastic praise would enhance the glorious reverberations from the event itself and support the crusading movement. In this way the transmission and reception of First Crusade letters represented a form of “scribal crusading. ”