What is Historia Caroli Magni?

Historia Caroli Magni , also known as Historia Karoli Magni et Rotholandi and sometimes as the Turpin Chronicle or the Pseudo-Turpin Chronicle, is a 12th-century Latin forged chronicle of legendary material about Charlemagne's alleged conquest of Spain. It is also called Book IV – The Conquests of Charlemagne of the Codex Calixtinus. The chronicle states it was written by Charlemagne's contemporary Turpin, Archbishop of Reims, but it was found out as a medieval forgery. The work was extremely popular, and served as a major source of material on Charlemagne in chronicles, fiction and iconography throughout Medieval Europe. The miracles of the flowering lances and the death of Ferracutus appear on the windows of Chartres cathedral.