The First Crusade is one of the most intensively researched events of the Middle Ages, yet, paradoxically, the manuscript source base for the letters from the expedition is almost entirely unexplored and represents an exciting new avenue of investigation for crusade studies. This article publishes the texts of three new manuscript witnesses of First Crusade letters and explores their regional reception and transmission as a form of “scribal crusading” — that is, monastic participation in the crusades from behind cloister walls. The findings of this article reveal an extremely significant, but previously underappreciated, collective impulse among German monastic communities in the twelfth and thirteenth centuries to participate in the crusading movement through the copying of First Crusade letters.