The land of Ishmael was a part of the land of Nephi, named after the sons of Ishmael, who had become Lamanites. It was governed by the Lamanite king Lamoni, himself a descendant of Ishmael. Ammon, a Nephite and one of the sons of Mosiah, came to the land around 90 B.C. (Alma 17:19, 21).
Ammon’s preaching converted King Lamoni, who believed his words (Alma 18:40), and many of the people, who were baptized and established a church among them (Alma 19:33–36). Lamoni had synagogues built throughout the land of Ishmael and gathered his people to worship (Alma 21:20).
The converts laid down their weapons and would not fight against their brethren (Alma 23:7-9; 24:5–6), which left them open to attack from the unconverted Lamanites. These converts, called Anti-Nephi-Lehies, gathered in the land of Ishmael, where Ammon, Lamoni, and Lamoni’s brother Anti-Nephi-Lehi held a council on how to defend themselves against the Lamanite forces (Alma 24:5).
Earlier, when Lamoni’s father commanded him to slay Ammon and return to the land of Ishmael, Lamoni refused, declining to kill Ammon and going instead to the land of Middoni to free Ammon’s brethren (Alma 20:14-15).