There may have been some overlapping in the four years of peace and the actual calendar years. Sometime in the year A.D. 326, Mormon turned fifteen years of age (v. 15 below), since he was born in the year A.D. 311. He was ten years old in A.D. 321 when Ammoran instructed him concerning the records (vv. 2–4 above). Therefore, the four-year peace seems to have been from sometime in A.D. 322 to sometime in A.D. 326.
During the time of external peace, there certainly was no internal peace, speaking collectively and generally. Wickedness prevailed to the extent that the beloved disciples were taken away (v. 13). At what time period the Lord ceased to have new disciples ordained as others passed away (see 4 Nephi 1:14) we do not know, but the beloved disciples taken away at this time seems to refer to the three who were promised they could tarry on the earth until the Second Coming of Christ (see 3 Nephi 28:7). However, the other nine members of the Twelve were also gone since there were no miracles, gifts, or guidance from the Holy Ghost among the people collectively (Mormon 1:13–14). The special witnesses of the Savior had apparently all departed through death, and the three transfigured men were transferred to another area of the earth to perform another work of the Lord. Notice that the three were “taken out of the land” (v. 16 below), not to Christ, nor to the kingdom of Christ as the others had been promised (see 3 Nephi 28:2–3).