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According to the Book of Mormon, Antionum was a Nephite military commander under the prophet-general Mormon and lived during the 4th century. During the final war between the Nephites and the Lamanites, at the cataclysmic Battle of Cumorah, Antionum and his entire army of ten thousand men were killed, along with the other dozens of Nephite military commanders and their armies of ten thousand apiece. The Battle of Cumorah marked the end of the Nephite civilization.