Alma 48:2

and thus he did inspire their hearts against the Nephites, insomuch, that in the latter end of the nineteenth year of the reign of the Judges, he having accomplished his designs thus far; yea, having been made king over the Lamanites, he sought also to reign over all the land; yea, and all the people which were in the land; the Nephites as well as the Lamanites;

He turned their hearts against the Nephites. By the end of the nineteenth year, he had done what he planned. He had become king of the Lamanites. He wanted to rule over all the land. He wanted to rule all the people in the land. He wanted to rule the Nephites and the Lamanites.

He stirred up their anger so effectively that by the end of the nineteenth year of the judges, he had achieved everything he wanted. He was now king over the Lamanites, but he wanted more—he wanted to rule over everyone in the land, both Nephites and Lamanites.