Crusade epic and hagiographic texts borrowed plot motifs from each other

Evidence

The similarities between this section of the Chanson and sections of Passion of Thiemo may indicate that the author of the Passion was familiar with the Chanson or vice versa. This section is probably one of the passages added by Graindor de Douai in the late twelfth century (Duparc-Quioc, 105). Later writers, including Marco Polo, also tell of the legendary three brother-kings (see Chanson d’Antioche, 269n). — John V. Tolan, Saracens, 1712