The origins of the Septuagint (hereafter, LXX) remain murky despite the evidence of its wide dissemination in the Hellenistic world. Clues to its existence begin to emerge as early as the mid-second century B.C. Historical details, however, concerning the identity, provenance, and setting of the translators are relatively scant. Clearer is the fact that by the end of the first century A.D. the books of the Greek Bible enjoyed a wide circulation among Christians and Hellenistic Jews and that by the end of the fourth century the first nearly complete manuscripts that have survived to the present day appeared, by which point the church had confirmed the books as canonical Scripture. The principal sources concerning the origin of the LXX are a likely-pseudonymous letter (Letter of Aristeas to Philocrates) and a refracted historical allusion (by the Jewish philosopher Aristobolus, recorded by Alexander Polyhistor and quoted by Clement of Alexandria [ca. A.D. 150–215] and Eusebius of Caesarea [ca. A.D. 260–340]). I will consider the credibility and claims of these two sources in turn, followed by a survey of three other potentially independent sources.
The Letter of Aristeas
Since I will survey the Letter of Aristeas more fully in a later discussion, my objective here is simply to outline its claims to gain some initial context. The letter purports to be an eyewitness account by a pagan Greek at the royal court of Ptolemy II Philadelphus (285–246 B.C.). Aristeas affirms that Philadelphus, desiring to amass all the world’s books at his library, was informed by his royal librarian, Demetrius of Phalerum, that the library lacked a copy of the laws of the Jews. He consequently sent a letter by the hand of Aristeas and others to Eleazar, the high priest in Jerusalem, soliciting six erudite elders from each tribe to produce a translation. In response, seventy-two Jewish scholars travelled from Jerusalem to Alexandria, Egypt, and, after seven days of banqueting and discussing philosophy, were sequestered in sumptuous accommodations during a period of seventy-two days as they completed the translation for inclusion in the royal library. Although the letter contains several historical inaccuracies, it provides both the basic time frame in which most scholars place the initial translation of the Pentateuch (ca. 280–250 B.C.) and the most likely location (Alexandria).
The secondhand historical account of Aristobolus is fragmentary. Aristobolus of Paneas was a Jewish Hellenistic philosopher in the first half of the second century B.C. who championed the compatibility of Jewish religion with Aristotelian philosophy. The author of 2 Maccabees identifies Aristobolus as belonging to the “family of the anointed priests” and as the “teacher of King Ptolemy,” presumably Philometer VI (181–145 B.C.) (2 Macc 1:10 [NETS]). Notable for my purpose here is his claim, cited by Clement of Alexandria, that portions of the Pentateuch had been translated into Greek prior to the translation of the entire Torah, which he also contends was completed in the days of Ptolemy Philadelphus. Aristobolus avers that portions of these earlier translations had reached Pythagoras, Socrates, and Plato, and had influenced their philosophies. Eusebius, agreeing in several details, likewise deems Aristobolus a “most distinguished scholar” and alleges that he was himself one of the elders who translated the Pentateuch in the days of Ptolemy II Philadelphus and of his father.
Other Sources Attesting to the Origins of the LXX
Three other, possibly independent, sources merit mention. The Hellenistic Jewish philosopher Philo (ca. 20 B.C.–A.D. 50) recounts the translation of the LXX Pentateuch in his tractate Life of Moses. Although his account is likely an embellishment and a polemic for the superiority of the LXX, he adduces several items absent from Aristeas. Philo claims that the translation was divinely inspired (making its authority equivalent to the Hebrew), that the translation took place on the Island of Pharos, that each of the translators independently rendered identical wording, that the translators were carried away with the gift of prophecy so as to render their translation identical with the Hebrew, and that an annual feast was held on the Island of Pharos to commemorate the event. Two other sources attesting to its origin are Christian: fourth-century Cyprian bishop Epiphanias (ca. 367–403) and twelfth-century Byzantine linguist and scholar Johannes Tzetzes (1100–1180). In his treatise On Weights and Measures, Epiphanius recounts the circumstances surrounding the translation of the Pentateuch. Collins notes that Epiphanius presents at least two details not mentioned by Aristeas or Philo, including the existence of two libraries in Alexandria and the name of the tribe to which each of the seventy-two translators belonged. This may constitute independent testimony to the historicity of the account. In his preface to the Plutus of Aristophanes, Johannes Tzetzes likewise outlines the historical origins. He includes several items otherwise unattested by Aristeas, such as the names of two royal translators under the patronage of Ptolemy II Philadelphus, a description of the two libraries in Alexandria, and the number of volumes in each library. These additional sources collectively provide some corroboration to the basic historical narrative presented by Aristeas.
Linguistic and Cultural Factors
Beyond these sources, other factors support an early third-century B.C. translation of the Pentateuch. Several Hellenistic Jewish writers from the end of the third century to nearly the beginning of the Christian era (ca. 200–50 B.C.) give evidence of knowledge of the Greek Bible, including Demetrius, Eupolemus, Ezekiel, and Aristobolus. Likewise, several later books of the LXX echo the phrasing of the Septuagint Proper (Pentateuch). In addition, the Greek of the LXX Pentateuch displays a stage in the linguistic development of Koine that fits neatly in the early third century. Further, other historical accounts describing the urbane and erudite culture fostered by Ptolemy II Philadelphus provide evidence agreeing with the conclusion that his reign was the setting for the translation. Finally, papyri witnesses from the second century B.C. (Rylands 458) and first century B.C. (Fouad 266) contain fragments of LXX Deuteronomy, attesting to a terminus ad quem (i.e., latest possible date) for the Pentateuch.
The LXX Translation of the Other Books
As to the translation of the Prophets and the Writings, no historical account of their translation survives, so we are left to reconstruct the most plausible scenario from internal evidence, at times on a book-by-book basis. The translation of the historical books is thus usually placed in the second to early-first century B.C., the prophetic books in the mid-second century B.C., and the wisdom books in the latter half of the second century B.C. As to location, opinions are divided and historical evidence is lacking. Muddling the question, moreover, is the reality that one would expect translators from Jerusalem producing a translation for an Egyptian audience to incorporate some linguistic elements from both locations. Thus, as noted by Dines, while the colophon (i.e., the editorial addition to the conclusion) of Esther suggests a Palestinian origin, the prologue to Sirach and the vocabulary of LXX Isaiah hint at an Egyptian provenance. Tov observes that most scholars simply assume an Alexandrian origin for the remainder of the LXX based on analogy with the Pentateuch and due to certain perceived connections to Egyptian-Greek and demotic languages. He counters, however, that the default assumption should be a Palestinian origin due to several lines of evidence. First, the colophon of Esther identifies the translator as “Lysimachus, son of Ptolemy, one of those in Jerusalem” (τῶν ἐν Ιερουσαλημ) (nets). The phrase ostensibly implies a Palestinian provenance. Second, LXX Ecclesiastes was likely translated in Palestine by Aquila or by kaige-Theodotion, while portions of LXX Samuel–Kings, Canticles, Lamentations, and Ruth were also probably translated there by kaige-Theodotion. Third, the translation of the post-Pentateuchal books could not have been produced by Egyptians, who had lost facility in Hebrew. Fourth, the translation of the rest of the Hebrew Bible likely did not take place under royal patronage in Alexandria because the other books did not carry the same authority as the Torah and only the Torah is mentioned explicitly as the desideratum of Philadelphus for his library.
On the basis of numerous historical and linguistic factors, the LXX Pentateuch was likely translated ca. 280–250 B.C. in Alexandria, Egypt. No historical accounts verify the translation of the remainder of the OT, leaving us to rely on linguistic and situational factors. The most likely scenario is that the rest of the LXX books—Historical, Prophetic, and Poetic—were translated ca. 200–100 B.C., chiefly in Palestine.
 Jennifer M. Dines, The Septuagint (New York: T&T Clark, 2004), 27.
 For background and an English translation, see R. H. Charles, ed., The Apocrypha and Pseudepigrapha of the Old Testament, 2 vols. (Oxford: Clarendon Press, 1913), 2:83–122.
 ABD, s.v. “Septuagint,” by Melvin K. H. Peters, 5:1096. For an overview of the life and era of Ptolemy II Philadelphus, see Paul McKechnie and Philippe Guillaume, eds., Ptolemy II Philadelphus and His World (Leiden: Brill, 2008).
 The chief historical incongruity is that Demetrius of Phalerum never served as Philadelphus’s royal librarian, having been banished by the latter when he acceded to the throne (as affirmed by Diogenes Laertius and Cicero). Nina L. Collins disputes this claim, however, as based in part on an error in chronology, leading her to conclude that Aristeas is, in fact, correct in linking Demetrius to Philadelphus (The Library in Alexandria and the Bible in Greek [Leiden: Brill, 2000], 58).
 EncJud, s.v. “Aristobulus of Paneas,” by Joshua Gutmann, 3:443–44.
 Clement of Alexandria, Stromata, 1.22, in Ante-Nicene Fathers, ed. Alexander Roberts and James Donaldson (reprint ed., Peabody, MA: Hendrickson, 2004), 2:334.
 Eusebius of Caesarea, Ecclesiastical History, 7.23, in Eusebius’ Ecclesiastical History (reprint ed., Grand Rapids: Baker, 1955), 313; idem, Preparation for the Gospel, 13.12, trans. Edwin H. Gifford, 2 vols. (reprint ed., Grand Rapids: Baker, 1981), 2:718–19.
 Philo, Moses, 2.28–44. See The Works of Philo, trans. C. D. Yonge (updated ed., Peabody, MA: Hendrickson, 1993), 493–44.
 See the discussion in Natalio F. Marcos, The Septuagint in Context: Introduction to the Greek Versions of the Bible, trans. Wilfred G. E. Watson (Leiden: Brill, 2000), 48.
 Collins, The Library in Alexandria, 60–61. For an overview of Epiphanius (ca. 367–403), see Andrew Jacobs, Epiphanius of Cyprus: A Cultural Biography of Late Antiquity (Berkeley: University of California Press, 2016).
 See Epiphanius’ Treatise on Weights and Measures: The Syriac Version, ed. James E. Dean, SAOC 11 (Chicago: University of Chicago Press, 1935). Available online at https://oi.uchicago.edu/sites/oi.uchicago.edu/files/uploads/shared/docs/saoc11.pdf, accessed 12 June 2019.
 Epiphanius, Weights and Measures, §53c (Dean, 27).
 Ibid., §51d–52a (Dean, 24).
 For the original Greek, see Georgius Kaibel, Comicorum Graecorum Fragmenta (Berlin: Weidmann, 1899), 19–20, 31. For an English translation, see Collins, The Library in Alexandria, 60–61.
 Henry B. Swete, An Introduction to the Old Testament in Greek, rev. Richard R. Ottley (New York: KTAV Publishing, 1968), 370–71.
 See Swete, The Old Testament in Greek, 371–72; Dines, The Septuagint, 42.
 J. A. L. Lee, A Lexical Study of the Septuagint Version of the Pentateuch, SCS 14 (Chico, CA: Scholars Press, 1983), 145–49; T. V. Evans, Verbal Syntax in the Greek Pentateuch: Natural Greek Usage and Hebrew Interference (Oxford: Oxford University Press, 2001), 263.
 See Oswyn Murray, “Ptolemaic Royal Patronage,” in Ptolemy II Philadelphus and His World, ed. Paul McKechnie and Philippe Guillaume (Leiden: Brill, 2008), 9–24.
 Marcos, The Septuagint in Context, 40.
 See Dines, The Septuagint, 45–47.
 Ibid., 46–47.
 Emanuel Tov, The Text-Critical Use of the Septuagint in Biblical Research, rev. 3rd ed. (Winona Lake, IN: Eisenbrauns, 2015), 202.
 See Elias J. Bickerman, “The Colophon of the Greek Book of Esther,” JBL 63 (Dec 1944): 339–62.
 Tov, The Text-Critical Use of the Septuagint, 203–4.