The book of Mosiah begins by stating that there was "no more contention" but "continual peace" (Mosiah 1:1). For the book to begin this way, the implication is that there had been serious problems with disunity in the Land of Zarahemla prior to this time (indeed, see Words of Mormon 1:12). Many Mulekites and a few Nephites lived in Zarahemla. Even counting all of the Nephites, Jacobites, Josephites, and Zoramites together, there were still more Mulekites than Nephites, as Mosiah 25:2 makes clear. This mixed population had needed to fight off Lamanite armies. False Christs had arisen, and Benjamin had to "shut their mouths" and punish false prophets and dissidents. These challenges long persisted in that region. While Benjamin’s power was challenged by some of his subjects, he labored tirelessly with his whole body and soul to reestablish peace throughout his land (Words of Mormon 1:12–18).
How was it that Benjamin’s father had become king in Zarahemla in the first place? In ancient America and in other parts of the world, it was common enough for an outside manager to be brought in to take care of local political and managerial jobs. When people from within the city were deciding who got certain privileges, it could engender hard feelings, so an outside person was sometimes brought in to rule the city for ten years or so. The decisions of such an administrator may have angered some, but they figured that he would be moving on. This was a common enough practice that Professor John Sorenson has speculated that when Mosiah1 came from the Land of Nephi, he was welcomed as a leader because he had records, language, wisdom, and administrative experience. However, after some time had passed, the older, indigenous population may well have tired of being ruled by an outsider. Mosiah1 had certainly ensconced himself and his son, King Benjamin. But a generation after Benjamin’s death, and after King Mosiah2 had stepped down and died and the reign of the judges replaced the monarchy, a group of people called king-men stepped forth who wanted the kingship back. One such alternative heir-apparent might well have been a descendant of Zarahemla, whom the Amlicites gladly sponsored.
In any event, these pressures show that, while there were persistent hard feelings to deal with, King Benjamin and his son Mosiah were still able, for the most part, to unite these people. We should not pass lightly over this achievement. It was a major accomplishment, as these kings called upon every possible tool of law, ethics, oratory, prophecy, doctrine, and covenant-making to preserve and protect their people.
Book of Mormon Central, "Why Should Readers Pay Close Attention to the Mulekites? (Omni 1:19)," KnoWhy 434 (May 17, 2018).
Book of Mormon Central, "What Did it Mean to be ‘King Over All the Land’? (Alma 20:8)," KnoWhy 128 (June 23, 2016).
John L. Sorenson, Mormon’s Codex: An Ancient American Book (Salt Lake City and Provo, UT: Deseret Book and the Neal A. Maxwell Institute for Religious Scholarship, 2013), 362–380.