With Amalickiah dead, his brother Ammoron became king over the Lamanites. In 63 BC, Moroni wrote to him, saying, "I would warn you of the awful hell that awaits murderers like you and your brother, but it would be in vain, for you are a child of hell. So I tell you this: unless you return our lands and retreat, I will come after you, arming even our women and children, and we will follow you back to your lands and kill all your people until the Lamanites are destroyed from the face of the earth."
Moroni's letter angered Ammoron, and the Lamanite king wrote back: "You threaten us, be we do not fear your threats. You murdered my brother, and I will avenge his death. Your ancestors robbed ours of their rightful position as rulers, so we will return control over the lands to whom they rightfully belong, then there will be an end to war. We don't claim to know if there is a God or a hell, but if there's a hell, then surely that is where you will end up."
When Moroni read the reply, he was even angrier than before, and so the war continued. Years earlier the converted Lamanites known as Ammon's people had vowed never to take up weapons again, and they faithfully kept their vow. But the children of those people were now coming of age and 2,000 of their young men were eager to help defend the Nephite lands. And Helaman, the son of Alma the younger, was made their leader.
Now the Lamanites could not be attacked in their well-defended cities, so the Nephites came up with a plan. Helaman and his band of 2,000 young men disguised themselves as supply-carriers and they took a path between two Nephite cities that caused them to come within view of a fortified city controlled by the Lamanites. The ruse worked and the most powerful of the Lamanite armies came out and gave chase to them.
A Nephite army followed them, and when they were a long distance from the city, they attacked the Lamanites from the rear while Helaman and the 2,000 young men turned around and attacked from the front. Despite having never fought before, the 2,000 young men had no fear of death, for their mothers had taught them that if they did not doubt, God would protect them, and indeed they fought with miraculous strength.
So many of their soldiers were killed so quickly by the 2,000 young men that the Lamanites became frightened. They threw down their weapons and offered themselves up as prisoners of war. Although there were many Nephite casualties, Helaman counted up the 2,000 young men and not one of them had been killed. The prisoners of war were marched off to Zarahemla.
Then Ammoron made an offer to Helaman, saying he would return control the fortified city they were stationed in to the Nephites if Helaman would agree to release the Lamanite prisoners of war. But Helaman wanted to take the city by force and would not release the prisoners. After another Nephite victory at Cumeni, there were so many Lamanite prisoners of war that the Nephites could not keep them under control, and they put to death more than 2,000 of the men who had surrendered to them.
Ammaron then attacked the Nephites at Cumeni with another Lamanite army, and Helaman and the 2,000 young men fought desperately against them, administering death to all who opposed them. The rest of the Nephite army was about to give way to the Lamanites, but the 2,000 young men stood firm and undaunted and they were protected because of their faith their mothers had taught them.
The Lamanite army retreated to Manti, and the Nephites tended to their wounded. 1,000 Nephites died in the fighting. Out of the 2,000 of Helaman's young men, 200 of them had fainted from loss of blood, and the rest also received many wounds, but to the astonishment of the whole Nephite army, not a single one of them had been killed.