Teancum was a prominent Nephite military leader during the late war periods of the Book of Mormon narrative, renowned for his valor and tactical ingenuity. His noteworthy military service began in earnest around 67 BC when he successfully quashed the rebellion led by the dissident Morianton, proving his capability in combat by personally slaying the rebellion’s leader (Alma 50:35). Known for his confrontations with notorious adversaries, Teancum made a decisive mark in the conflict between the Nephites and the Lamanites, which had been exacerbated by Nephite dissenters aligning with the Lamanite force.
In a subsequent campaign, led by the defector Amalickiah, the Lamanites suffered defeat at the hands of Teancum. That night, with a daring and solitary infiltrative maneuver, Teancum succeeded in assassinating Amalickiah, employing a javelin to claim the life of the sleeping Lamanite king (Alma 51:33-34). This act of lethality caused a significant shift in Lamanite military objectives and led to a temporary withdrawal from intended northern conquests.
Further demonstrating his martial dexterity, Teancum played a central role in regaining the strategic city of Mulek. Teancum and Moroni formulated a strategy to draw the Lamanite forces out and secure a pivotal triumph over them (Alma 52:21-26). Teancum’s relentless work secured the city of Bountiful, converting it into a stronghold, fortified assiduously by the labor of captured enemies (Alma 53:3-5).
In the latter part of his military career, Teancum, alongside Lehi, shouldered the responsibility of the Nephite armies during Moroni’s absence, when he left to assist the chief judge Pahoran (Alma 61:15; 62:3). Teancum’s service continued until approximately 60 BC, when his personal vendetta against the Lamanite generals, whom he blamed for years of devastating war, reached its climax. Unable to temper his rage against Ammoron—the brother and successor of Amalickiah—Teancum once again embarked on a solitary nocturnal mission, where he assassinated Ammoron in a manner akin to his earlier covert operation. However, this time fate did not side with the stealthy Nephite, and after killing Ammoron, Teancum was discovered and subsequently slain by the Lamanite guards (Alma 62:36).
Mormon, the Nephite record-keeper, esteemed Teancum posthumously as a “true friend to liberty” who had contended ardently for his people, enduring a multitude of severe afflictions throughout his service (Alma 62:37). His narrative thus concludes as one of courage, fierce patriotism, and the lasting impact of a commander pivotal to the Nephite defense against persistent enemies.