The character "Gisle" is based on the real life Norwegian Jarl "Håkon the Crazy". The name was changed to avoid confusion in a movie that already have two Håkons. Jarl Håkon was also never directly antagonistic towards his brother, Inge, even though they are said to have had a shaky relationship at best.
One of the publicity stills from the movie, which is shown on the back of the disc case and in the disc menu, is a recreation of the famous painting "Birkebeinerne på Ski over Fjeldet med Kongsbarnet" by Knud Bergslien. This painting is now housed in the Holmenkollen Ski Museum in Oslo, and shows the two rescuers on skis; one is holding an axe in one hand and cradling the infant in the other arm, and the other rescuer is holding a spear with both hands.