In Mormon 6:2, Mormon records that "I Mormon, wrote an epistle unto the king of the Lamanites." According to Hunter and Ferguson, there is an interesting comment from Ixtlilxochitl relating to an event which occurred nearly 500 years after Mormon's time [but which correlates with Mormon's statement]. Topiltzin (king of Tula - near what is now Mexico city), seeing himself so oppressed and that there was no way out (of military confrontation), asked for time, for it was a law among them that before a battle they would notify each other some years in advance so that on both sides they would be warned and prepared. (xcl) [Milton R. Hunter and Thomas Stuart Ferguson, Ancient America and the Book of Mormon, p. 361]
Geographical [Theory Map]: Mormon 6:1-5 Mormon Writes to the Lamanite King--the Nephites Will Gather to Cumorah (381 A.S.)