According to legend, Bertold embarked on the traditional quest to rediscover the lost kingdom of Chalsembyr, the realm of the once-mortal Torm. To aid him in this endeavor, clerics of the House of the Hand temple in Procampur, the Vast, forged Chalsembyr's Heart. Bertold carried the sword with him on his journeys.
Finally, while crossing the Toadsquat Mountains of the southeastern Shaar, Bertold was ambushed by ogres and slain. He was unaware of his sword's soul binding power, however, and rather than go to the House of the Triad, Bertold's soul went into Chalsembyr's Heart, becoming an intelligent weapon.
There her would remain until another found and claimed the sword, to become the beneficiary of Bertold's knowledge and experience. However, the sword was lost after Bertold's death and not found by 1374 DR. Many paladins of Torm sought it around Faerûn. The legend told that if another paladin wielded Chalsembyr's Heart and died, then their soul would also go into the sword, freeing Bertold to finally ascend to the afterlife.
Among paladins, Bertold was particularly devout in his faith and possessed of great dedication and unselfishness. As the sword Chalsembyr's Heart, Bertold the Seeker was a wise and charismatic soul.
Bertold, in sword-form, was knowledgeable in history with regards to Chalsembyr and in deciphering ancient and obscured writings.