Historia belli sacri

The Historia belli sacri, also called the Historia de via Hierosolymis or Historia peregrinorum, is a chronicle of the First Crusade and the early years of the Crusader states written by an anonymous monk of the Abbey of Montecassino. It covers the years 1095–1131 and must have been mostly compiled around 1130. It is sometimes called the "Monte Cassino Chronicle" for simplicity.

The Historia belli sacri is based in large part on the equally anonymous Gesta Francorum and also incorporating fragments from the Historia Francorum qui ceperunt Iherusalem, the Gesta Tancredi and other unknown texts. Although heavily reliant on the Gesta Francorum, it is an important source for the Italo-Norman crusaders. Like the histories of Robert the Monk and Guibert of Nogent's Dei gesta per Francos, both of which were used as sources by its anonymous author, the Historia belli sacri is "a serious and careful effort to rework the Gesta story and add to it significant information which is not found in any other source." It was, after all, "written in an age when there were still survivors of the First Crusade."

There is a complete English translation.