Amaleki1 tells us that he was born during the time of Mosiah1 and lived during the reign of Mosiah1's son, Benjamin (Omni 1:23). In fact, when Amaleki1 grew old he entrusted the small plates of Nephi to Benjamin (Omni 1:25). Then Amaleki1 finishes his record with this account:
And now I would speak somewhat concerning a certain number who went up into the wilderness to return to the land of Nephi; for there was a large number who were desirous to possess the land of their inheritance. Wherefore, they went up into the wilderness. And their leader being a strong and mighty man, and a stiffnecked man, wherefore he caused a contention among them; and they were all slain, save fifty, in the wilderness, and they returned again to the land of Zarahemla. And it came to pass that they also took others to a considerable number, and took their journey again into the wilderness. And I, Amaleki1, had a brother, who also went with them; and I have not since known concerning them. And I am about to lie down in my grave; and these plates are full. And I make an end of my speaking. (Omni 1:27–30).A few pages later in the Book of Mormon we get a fuller account of this expedition which left to resettle the Land of Nephi. Around 121 BC (Mosiah 7:2; ) Ammon1, Amaleki2, and fourteen others are sent by Mosiah2 (the son and successor of Benjamin) to go looking for them (Mosiah 7:1–6). At this point we learn that the leader of the expedition was named Zeniff and that his grandson, Limhi, is now the leader of those people (Mosiah 7:9). Chapters 9–22 of the Book of Mosiah are an account of the people of Zeniff from the time that they left until they escaped back to Zarahemla with the help of Ammon1. Additionally, chapters 23–24 are an account of the followers of Alma1, from the time that they left during the reign of Noah3 (Zeniff's son and Limhi's father) until they find their way to Zarahemla.
The first part of Zeniff's account (Mosiah 9:1–3) confirms that this is the group that Amaleki1 mentioned and that they left around 200 BC. They return to the Land of Nephi and convince the Lamanite king there to let them re-settle part of the land. They name this smaller portion that they're allowed to resettle the Land of Lehi-Nephi. Despite his over-zealousness (Mosiah 7:21; 9:3; ), Zeniff tried to be a righteous leader. His son, Noah3, however, did not. Under the reign of Noah3 the people engaged in idolatry and lasciviousness (Mosiah 11). At some point during Noah3's kingship (around 150 BC) a prophet comes to them decrying their wickedness. His name was Abinadi. The people of the land of Lehi-Nephi reject Abinadi and try to kill him but he escapes them (Mosiah 11:20–29). Two years later (around 148 BC) the Lord sends Abinadi back (Mosiah 12:1). He is captured by Noah3 and eventually martyred—but not before he convinces some of the people (particularly Alma1) to repent (Mosiah 17).
Since Amaleki1 records the departure of Zeniff's group (which included his unnamed brother) while Mosiah1 was king, we know his reign lasted at least until around 200 BC. Since Amaleki1 mentions Mosiah1 and his father Abinadom (Omni 1:10–21) does not, I suspect that Amaleki1 had already taken over the record-keeping by that point. Thus Amaleki1 must have come into possession of the small plates of Nephi sometime before 200 BC. Moving on, Mosiah2 takes the throne around 124 BC at the age of 30 (Mosiah 6:4). This means he was born around 154 BC. This gives us an approximate time at which his father, Benjamin, could've assumed the throne (around 150 BC). But Amaleki1 really could've given Benjamin the small plates of Nephi at any time during his reign. So Amaleki1 was in possession of the small plates of Nephi sometime from around 200 BC (at the latest) to around 124 BC (at the latest). Realistically, though, Amaleki1 probably wasn't younger than 15 when he took charge of the plates and there's no evidence that the Nephites had unusually long lifespans. So by the time I've estimated that Benjamin took the throne (around 150 BC), Amaleki1 would've been at least 65 years old (or probably older) and near the end of his life (Omni 1:30). Furthermore, Words of Mormon 1:10–18 recounts most of the doings of Benjamin—doings which are not mentioned by Amaleki1. This would suggest that Amaleki1 turned the records over to Benjamin near the beginning of his reign.
If Amaleki1's brother wasn't killed in one of the many skirmishes between the people of Zeniff and the Lamanites (Mosiah 9:14–19; 10:6–20; 19:7–15; 20:6–12; 21:7–8, 11–12), then this gives us an approximate time frame for his life, too. So now let me present the reasons I suspect that Amaleki1's brother was none other than the prophet Abinadi who was put to death by Noah3 and his wicked priests. My first point relates to the chronology. Abinadi first began to preach around 150 BC (Mosiah 11:20) and was put to death around 148 BC (Mosiah 17:20). The text of the Book of Mormon doesn't indicate how old he was at this time, but he's traditionally depicted as an old man  (though I have previously mentioned that LDS art can sometimes be misleading ). By itself, this argument doesn't suggest that Abinadi is the brother of Amaleki1, only that he could be, given the time frame. However, it lends credence to my next argument.
Some of Abinadi's teachings are very similar to the teachings of Benjamin (cf. Mosiah 16:1 with 3:20; 16:5 with 2:38; and 16:10–11 with 3:2–25). This can be explained if Abinadi learned them from the records kept by his father and brother—the same records given to Benjamin by Amaleki1. Indeed, in Mosiah 16:1 Abinadi is interpreting a passage of Isaiah (52:8–10) that he'd just quoted (Mosiah 15:29–31) in response to a query by one of the priests of Noah3 (Mosiah 12:20–24). I found this correlation between Abinadi's discourse and that of Benjamin in The Encyclopedia of Mormonism , but the author of that article proposed that perhaps Abinadi spent time in Zarahemla between the two times he came to the Land of Nephi to preach and thus was simply repeating doctrines he'd learned from Benjamin. I find this to be unlikely, though, since 1. Mosiah2 had no idea how the followers of Zeniff had fared (Mosiah 7:1) and presumably he would've if Abinadi had been traveling back and forth; and 2. the dates provided in the footnotes of the Book of Mormon place Abinadi's discourse to Noah3 around 148 BC and Benjamin's discourse to the people of Zarahemla around 124 BC, just before Mosiah2 takes the throne—nearly 25 years later.
Finally, Amaleki1's father was named Abinadom (Omni 1:12), which is very similar to Abinadi's name. I don't know enough about Hebrew naming conventions to say how often fathers passed their names on to their sons. A quick perusal of a few of the "begat" lists in the Bible  didn't reveal any, but there are a few instances in the Book of Mormon : Shez1 named a son after himself (Shez2); Alma1 named a son after himself (Alma2); Helaman2 named a son after himself (Helaman3); Mormon1 named a son after himself (Mormon2); Pahoran1 named a son after himself (Pahoran2); Lachoneus1 named a son after himself (Lachoneus2); Laman2 named a son after himself (Laman3); Nephi2 named a son after himself (Nephi3), who also passed on the name to his son (Nephi4); Amos1 named a son after himself (Amos2). We also have Mosiah2 named after his grandfather (Mosiah1)—a pattern which can be found in the Bible. But Abinadi isn't exactly the same as Abinadom. So what about cases in the Bible of fathers giving their sons similar names? I found a few and only one seemed to be bona fide . It is rare in the Book of Mormon, too: Moroni1 named a son Moronihah (Alma 62:43); Omer named a son Emer (Ether 1:29); and Corihor named a son Cohor (and his brother, Noah2, named one of his sons Cohor). Note that these last two are Jaredites, not Nephites or Lamanites (see note ). There were also brothers named Mathoni and Mathonihah. So while I can't say whether it's realistic that Abinadom would have a son named Abinadi (or Amaleki to have a son or grandson named Amaleki) under Hebrew naming conventions, it seems pretty likely under Nephite naming conventions.
Before I end, let me briefly visit the character of Amaleki2. I originally suspected that he was identical with Amaleki1 because the Index to the Triple Combination listed their estimated dates as 130 BC (Amaleki1) and 121 BC (Amaleki2). Thus he would be going to the Land of Nephi to find his lost brother. But after investigating the matter further (as expounded in the paragraphs above), I determined that Amaleki1 was likely no longer alive in 130 BC. Even if he was still alive, the fifteen who went with Ammon1 were all strong men (Mosiah 7:2); by this time Amaleki1 would've been at least 70 years old and not a "strong man". So now I'm leaning towards Amaleki2 being the grandson of Amaleki1. This would still give Amaleki2 a motivation to go on the expedition and to be one of the four men who actually ventured down into the Land of Nephi: to find out what happened to his great-uncle Abinadi. One mitigating note, though: Ammon1 was a descendent of Zarahemla (Mosiah 7:3, 13) and the text calls Amaleki2 one of his "brethren" (Mosiah 7:6), so it's possible that Amaleki2 was also a Mulekite, not a Nephite, like Amaleki1. However, I suspect that in this passage the word "brethren" simply refers to the fact that Amaleki2 was one of the other fifteen men on the expedition and doesn't imply consanguinity.
 The Book of Mormon is a record written by ancient peoples of the Americas and which was translated by Joseph Smith by the power of God. The major groups of people are referred to as Nephites, Lamanites, and Jaredites. To read the scriptures I cite herein, start here.
 Amaleki is just one of several Nephite/Lamanite names that seem to have a common element m-l-k. This could be derived from the Hebrew root מלך (m-l-ḵ), which means "king" or "to rule" (see here). Other (less likely) possibilities include:
- the Hebrew root מלח (m-l-ḥ), which means "salt" or "to dissipate" (see here)
- the Hebrew word מלאך (m-l-ʾ-ḵ), which means "angel" or "messenger" (see here)
- the Hebrew word מלה (m-l-h), which means "word" (see here)
- the Hebrew root מלק (m-l-q), which means "to break" or "to crush" (see here).
- Amalekiah (a Nephite traitor who lived around 50 BC—see Alma 46–51; also see notes [*] and [**] below)
- Amulek (a Nephite missionary who lived around 82–74 BC; see Alma 8–16, 34–35)
- Melek (a land in the territory of the Nephites; see Alma 8:3–4; 35:13; 45:18)
- Mulek (the son of the Israelite King, Zedekiah—see note ; he lived around 589 BC; see Mosiah 25:2; Hel. 6:10; 8:21; there are also a city (Alma 51–53) and a territory (Hel. 6:10) with the same name)
- Muloki (a Nephite missionary who lived around 90 BC; see Alma 20–21)
 For a fairly comprehensive diagram of the many different records that were compiled (and often abridged) into the Book of Mormon, see http://www.lightplanet.com/mormons/images/Basic BOM Plates 2.jpg. You can also read this description which is part of the introduction to the Book of Mormon.
 Individuals who share names are numbered according to their appearance, chronologically, in the unique books of LDS Scripture (the Book of Mormon, the Doctrine and Covenants, and the Pearl of Great Price which are often published together in a volume referred to as the Triple Combination). Thus the patriarch (Moses 7) is Noah1, the Jaredite king (Ether 7) is Noah2, and the evil Nephite king (Mosiah 11) is Noah3. On the other hand, the patriarch Benjamin never appears in the Triple Combination, so the Nephite King is designated Benjamin, not Benjamin2.
 The people of Zarahemla were not descendents of Nephi, but were descended from one of the sons of Zedekiah, named Mulek (see note ). These people are informally called Mulekites, after their progenitor, Mulek, but the word "Mulekites" doesn't actually appear anywhere in the Scriptures. It has been posited that the Mulek of the Book of Mormon is synonymous with the Malchiah ben Hammelech (i.e. "Malchiah, the son of the King") mentioned in Jer. 38:6 (see Tvedtnes, John A., Gee, John, & Roper, Matthew. (2000) "Book of Mormon Names Attested in Ancient Hebrew Inscriptions," Journal of Book of Mormon Studies, 9 (1): 40–51 and Chadwick, Jeffrey R. (2003) "Has the Seal of Mulek Been Found?" Journal of Book of Mormon Studies, 12 (2): 72–83.). For this to make sense you should understand that Mulek is an acceptable hypocorism (nickname) for someone named Malchiah.
 The dates I report are derived from the footnotes provided in the Book of Mormon (e.g. the date next to this footnote can be seen in the online edition of the Book of Mormon here, as a footnote to verse 2) and/or from the dates listed in the Index to the Triple Combination (available in its entirety here). The dates are best guesses, but there is thus far no definitive proof that they are completely accurate.
 For an interesting take on Zeniff, see Samuelson, Cecil O. (2011) "Appropriate Zeal." BYU Magazine Provo, UT: BYU).
 John A. Tvedtnes speculates that the name Abinadi could be derived from the Hebrew root אב (ʾ[a]-b "father") + נדד (n-d-d, "to wander"), with the possible meaning "father of my wandering". See Tvedtnes, John A. (2002) "Hebrew Names in the Book of Mormon." (.pdf), p. 3.
 I always feel a little chagrined for Abinadi in this verse. He enters the city in disguise so the people won't recognize him and try to kill him or turn him over to Noah. But as soon as he has their attention he tells them his name. Oops!
 This is at variance with the ca. 130 BC date reported for Amaleki1 in the Index to the Triple Combination (here; but see note ) However I feel I've made a good case for why the provided date would be inaccurate.
 See, for example, this painting of Abinadi by Arnold Friberg.
 See my post Lehi's Family.
 This passage of Isaiah is also quoted in 3 Ne. 16:18–20.
 Cramer, Lew W. "Abinadi" in Ludlow, Daniel H., ed. (1992) The Encyclopedia of Mormonism, vol. 1 (New York, NY: Macmillan Publishing Co.), pp. 6–7. ISBN: 002904040X.
 I checked Gen. 4, 5, 10–11, 22, 25; Num. 26; Ruth 4; 1 Chr. 1–9, 14; 2 Chr. 11; Neh. 12; Mt. 1; and Lk. 3. There also weren't any instances in the Jaredite record (Ether 1), but there you do have the interesting case, though, where there are two instances in the same line of a man named Coriantum who named a son Com (Ether 1:13 and 1:27; see also Ether 9:24–27 and Ether 10:31–11:4).
 Giving sons their father's name doesn't appear until after the Jaredite record is found—so perhaps it is a Jaredite custom adopted by the Nephites at this time.
 A few cases I've found: Nahor named after his grandfather (Gen. 11:24–26); Azariah named after his grandfather (1 Chr. 6:9–10); Benjamin named after his grandfather (1 Chr. 7:6, 10); Tahath named after his grandfather (1 Chr. 7:20); etc.
 Ehud named a son Ahihud (1 Chr. 8:6–7; if you follow the links you'll see that in Hebrew these are quite dissimilar); Shimhi named a son Shimrath (1 Chr. 8:21; if you follow the links you'll see that in Hebrew these are quite dissimilar); Imri named a son Omri (1 Chr. 9:4; if you follow the links you'll see that in Hebrew these are quite dissimilar); and Meshillemith named a son Meshullam (1 Chr. 9:12; this is the only case I could find where one name was likely derived from another).
 They were two of the twelve Nephite disciples called by Jesus Christ when he visited the American continent after His resurrection (3 Ne. 19:4). Interestingly, among the twelve disciples there were also a Kumen and a Kumenonhi (though there's no indication that they were related) and two men named Jonas.
[*] It has been proposed that Book of Mormon names that end in -iah or -ihah correspond to Biblical names that end in -iah or -ijah, which have the meaning "Jehovah" (see Nibley, Hugh. (1988) "Proper Names in the Book of Mormon", ch. 22 of An Approach to the Book of Mormon (Salt Lake City, UT: Deseret Book, Co.) ISBN: 0875791387; Nibley, Hugh. (1993) "Lecture 6: 1 Nephi 1; Jeremiah 29" in Teachings of the Book of Mormon: Semester 1 (Provo, UT: FARMS) ISBN: 1591565715; and Nibley, Hugh. (1993) "Lecture 45: Alma 4–5" in Teachings of the Book of Mormon: Semester 2 (Provo, UT: FARMS) ISBN: 1591565723.) Thus the name Amalickiah could mean something along the lines of "Jehovah is my king", which is unfortunate, given his apostasy. It is disputed however, that the -ihah ending refers to Jehovah (see Hoskisson, Paul. (2009) "It Is OK Not to Have Every Answer: The Book of Mormon Onomastic Ending -(i)hah." Journal of the Book of Mormon and Other Restoration Scripture, 18 (1): 48–55.).
[**] The Pronunciation Guide for the 1989 edition of the Book of Mormon erroneously suggests the pronunciation uh-mal-uh-KIH-uh (mouse over for IPA) for Amalickiah. This has been corrected in subsequent editions and online (see here) to uh-mal-uh-KAI-uh.