Nothing is known about Bercthun's early life. Frightening as they come, Bercthun was known to crush tortoises with his own bare hands. Bercthun was even stated to take immense satisfaction with killing these creatures. However, one warning is that if you were in his way with no tortoises in sight, you ran as fast as you could. Bercthun was observed by the Order and thus he was inducted into the Zealots. Within the Order, Bercthun became a delivery service and anything-for-hire exclusively for the Order member, The Bell.
In his rounds, Bercthun patrolled the area along the roads throughout northern Hamtunscire. It was during one such patrol that he was targeted and then fatally defeated by the Viking Eivor, who was allied with the Hidden Ones. After Bercthun's death, Eivor found a clue, which gave the title, The Bell. This clue led Eivor to to search the chain blockade along Ember River, in northeastern Suthsexe.
- Like other Zealots, Bercthun had particular fighting strategies and items in his weaponry. Upon Eivor's instigation, Bercthun wielded a Dane Axe, attacked with javelins, and lit his axe on fire whenever he could.
- For The Bell, Bercthun's clue is the same one Eivor received if she assassinated The Billhook.
- Like fellow Zealots Horsa and Hrothgar, Bercthun walked along the roads rather than on horseback, due to his grand size.