Coriantumr is the name of a Nephite dissenter who is appointed as a leader over the armies of Lamanite king Tubaloth, son of Ammoron and nephew of Amalickiah.
Tubaloth encourages the Lamanites to war against the Nephites after the recent upheaval over the judgement seat between the sons of Pahoran.
This risky tactic works, giving him access to Zarahemla's protection and supplies,[7] the first time in the history of Lehi's descendants that Lamanites have captured the capital.
[8] After seeing the Nephites fall due to a small number of present military,[7] Coriantumr decides to conquer the entire land beyond only the capital.
Lehi then routes them from Bountiful; Coriantumr's armies flee back to Zarahemla but are met by Moronihah on the way.