According to the Book of Mormon, Lachoneus was the chief judge of the Nephites during the time of the birth of Christ, or AD 1, the 92nd year of the reign of the judges. His reign started at a date unknown but not earlier than about 23-20 BC, the approximate time of the assassination of chief judge Cezoram .
No record of his life prior to the year AD 16 exists. In this year Giddianhi, leader of the band of Gadianton robbers at the time, sent Lachoneus a letter demanding that the Nephites surrender or be destroyed. Lachoneus rejected the demands and began preparations for war. He commanded his people to gather together in one place and there build fortifications against the robbers, appointed captains including Gidgiddoni, "great commander all the armies of the Nephites," and preached repentance . The people accepted his leadership and counsel, and the Nephites were eventually victorious .
Lachoneus died about AD 30 and was succeeded by his son, also named Lachoneus.