Ether 11:15 says that,
there arose a rebellion among the people [of King Moron], because of the secret combination which was built up . . . and there arose a mighty man among them in iniquity, and gave battle unto Moron, in which he did overthrow the half of the kingdom; and he did maintain the half of the kingdom for many years. And it came to pass that Moron did overthrow him, and did obtain the kingdom again.
The word "overthrow" seems to imply an internal conflict, but one might ask, From where did King Moron still reign over half of the kingdom? And from where did the "mighty man" reign over the other half of the kingdom? [Alan C. Miner, Personal Notes]