Pachus was king of a faction of Nephite dissenters around 62 B.C. He led a rebellion that drove the freemen and the chief governor Pahoran I out of Zarahemla, the Nephite capital, and took possession of the land. His rebels withheld provisions from the Nephite armies and kept reinforcements from reaching Captain Moroni in the field (Alma 61:3-5).
After seizing Zarahemla, Pachus’s faction wrote to the king of the Lamanites and joined an alliance with him, agreeing to hold the city to aid the Lamanite conquest, in return for which Pachus would be set up as king over the people once they were subdued (Alma 61:8). Pahoran fled to the land of Gideon, where Moroni united his forces with him; their combined armies outnumbered the men of Pachus. They marched on Zarahemla and met Pachus’s men in battle, in which Pachus was slain, his men taken prisoner, and Pahoran restored to the judgment-seat (Alma 62:6-8). The men of Pachus were tried alongside the captured king-men according to Nephite law, and those who would not take up arms in defense of their country were put to death (Alma 62:9-10).