What Is the Septuagint?

The Greek Scriptures behind much of the New Testament

By the first century AD, Greek-speaking Jewish communities across the Mediterranean had been reading Jewish Scripture in Greek for generations. The translations now grouped under the name Septuagint were not a curiosity or merely a Christian inheritance. They originated within Judaism and gave Greek-speaking Jewish communities access to the Torah and, over time, other scriptural books in the language many of them used every day. When the writers of the New Testament quoted Israel's Scriptures, their wording often agrees closely with these Greek translations.

That makes the Septuagint one of the most consequential translation traditions in the history of the Bible, and one of the easiest to oversimplify. It was not produced all at once, did not begin as a Christian Bible, and should not be imagined as one fixed ancient volume with exactly the contents of a modern Old Testament. This guide explains what the Septuagint is, what can responsibly be said about its origins, how Greek Jewish Scripture developed, why it became so important to early Christians, and how it still helps explain differences among Christian Bibles today. For the broader picture, our complete guide to what the Bible is lays the foundation this article builds on.

In its strictest historical sense, the name Septuagint refers to the ancient Greek translation of the Torah, while modern usage often extends the term to the wider collection of ancient Greek translations of Jewish scriptural books. These translations were produced over time, beginning in the Hellenistic period, with Alexandria playing a central role in the traditional account of the Torah's translation. The familiar abbreviation LXX reflects the tradition of seventy or seventy-two translators described in the Letter of Aristeas.

The Legend and the History: The Letter of Aristeas

Ask where the Septuagint came from and the traditional answer begins with a remarkable story. The Letter of Aristeas, a Hellenistic Jewish work probably written well after the events it describes, tells how Ptolemy II Philadelphus sought a Greek copy of the Jewish Law and how seventy-two Jewish elders — six from each of the twelve tribes — came from Jerusalem to translate it in Egypt. Later retellings developed the tradition further, emphasizing the translators' extraordinary agreement and the providential character of their work.

The Letter is invaluable evidence for how some Hellenistic Jews understood and defended the authority of the Greek Torah, but it is not a neutral eyewitness report. Modern scholars generally treat much of its elaborate narrative as literary and apologetic. The royal commission, the Alexandrian library setting, and the precise details surrounding the seventy-two translators therefore should not simply be repeated as established history.

What can be said more securely is narrower. The Greek translation of the Pentateuch is generally associated with Alexandria and the third century BC, and it was produced for a Jewish world in which Greek had become enormously important. The exact circumstances that initiated the translation remain debated. The name Septuagint — and the abbreviation LXX — preserves the ancient story of the translators even when the story itself is read critically.

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Not One Translation but a Gradual Project

This is the point most worth correcting in popular understanding: the Septuagint was not a single, fixed volume translated all at once. The Letter of Aristeas concerns the Torah — Genesis through Deuteronomy. Other Jewish scriptural books were translated into Greek over time by different translators, in different places and periods, and with noticeably different approaches. Some translations stay relatively close to their Hebrew source; others are freer, and in several books the surviving Greek and Hebrew forms differ in ways that cannot be explained by translation technique alone.

That is why scholars often use “Septuagint” in more than one sense. Strictly, the traditional name belongs to the Greek Pentateuch; more broadly, it has become convenient shorthand for the ancient Greek Jewish Scriptures and their textual traditions. Thinking of the Septuagint as a translation tradition rather than a single publishing event avoids importing the idea of a modern, bound Bible into a much more complicated ancient history.

The Dead Sea Scrolls made that complexity even clearer. Hebrew biblical manuscripts from the Judean Desert reveal textual forms that sometimes agree with the later Masoretic tradition, sometimes with readings reflected in ancient Greek translations, and sometimes with neither. The evidence must be examined book by book. It shows that the centuries before the stabilization of later textual traditions contained real textual plurality rather than one perfectly uniform Hebrew edition standing behind every ancient copy. The larger story of manuscripts, scribal transmission, and textual preservation is treated in our guide to how the Bible was written and preserved.

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The Septuagint in Second Temple Judaism

The Greek translations emerged from a Jewish world transformed by Hellenistic culture. Alexandria had a major Jewish population, and Greek became an important language of Jewish life across much of the eastern Mediterranean. Translation allowed Jewish Scripture to be read, studied, interpreted, and discussed in that wider linguistic environment. The history of Hebrew, Aramaic, and Greek within biblical culture is explored more fully in our guide to the languages of the Bible.

Philo of Alexandria, writing in the first century AD, treated the Greek Torah with profound reverence and even retold its translation in providential terms. Josephus later drew on the Aristeas tradition as well. Their testimony is important because it prevents a common historical mistake: the Septuagint did not begin as a Christian translation. Its origins and earliest reception were Jewish, long before Christians adopted Greek Scripture as their own Old Testament inheritance.

At the same time, Jewish use of Greek Scripture was not uniform everywhere, and “the Septuagint” should not be treated as though every Jewish community possessed or used an identical collection of Greek books. Different texts and textual forms circulated in a diverse Second Temple Jewish world.

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Why Greek Scripture Mattered to the Early Church

Christianity spread rapidly through a Mediterranean world in which Greek functioned as a major shared language. For many Greek-speaking Christian communities, the Jewish Scriptures they encountered and cited were Greek. Christians therefore did not invent a Greek Old Testament for themselves; they inherited Greek scriptural traditions that had already developed within Judaism and increasingly read those Scriptures in light of Jesus' life, death, and resurrection.

This inheritance shaped Christian language as well as Christian interpretation. The New Testament was written in Greek, and its authors repeatedly use vocabulary and scriptural phrasing familiar from the Greek Jewish Scriptures. Terms associated with covenant, righteousness, glory, law, and salvation entered Christian discourse within a linguistic world already deeply marked by Greek translations of Israel's sacred texts.

"Behold, the virgin shall conceive and bear a son, and they shall call his name Immanuel."

— Matthew 1:23, quoting Isaiah 7:14

Isaiah 7:14 is one of the best-known examples. The Hebrew text uses almah, a term referring to a young woman of marriageable age without making virginity its defining lexical meaning. The ancient Greek translation uses parthenos, a word that can denote a virgin and that Matthew reproduces when applying Isaiah's words to Jesus' birth. The important historical point is not that the Jewish translator was consciously predicting Matthew's later interpretation. It is that Matthew received a Greek wording already in circulation and read it christologically within the story he was telling.

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The Septuagint and the New Testament

The relationship between New Testament quotations and earlier Jewish Scriptures cannot be reduced to one percentage. Counts differ because scholars define quotations, textual agreements, and ancient textual forms differently. Even so, a large proportion of explicit Old Testament quotations in the New Testament agree closely with forms known from the Septuagint tradition, while others resemble Hebrew forms, combine traditions, or adapt wording to a new literary context.

The four Gospels repeatedly draw on Greek scriptural language, particularly when presenting Jesus in relation to Israel's Scriptures. Matthew's Gospel, with its recurring fulfillment formulas, offers especially visible examples. Paul's letters likewise contain extensive engagement with Greek Scripture as he argues about Abraham, covenant, law, faith, Israel, and the inclusion of the nations.

None of this requires imagining the New Testament writers as choosing between two neatly standardized Bibles labeled “Hebrew” and “Septuagint.” First-century Jewish Scripture existed in a more fluid textual environment than those modern labels suggest. The New Testament's quotations are therefore evidence both for the importance of Greek Scripture and for the textual diversity of the period.

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Why Jewish and Christian Greek Scriptures Diverged

As Christianity developed, Christians increasingly interpreted Greek Jewish Scripture in relation to Jesus. At the same time, Jewish scholars continued revising, translating, and interpreting Scripture within their own communities. New Greek versions associated with Aquila, Symmachus, and Theodotion testify to an active and varied Jewish engagement with the Hebrew text rather than to one simple rejection of Greek.

Christian appropriation of passages used in messianic argument was certainly part of the growing separation between Jewish and Christian scriptural cultures, but it was not the only cause. Linguistic change, evolving textual preferences, rabbinic interpretation, regional practice, and the broader historical separation of Judaism and Christianity all mattered. There was no single council or date at which “the Jews rejected the Septuagint.” The process unfolded unevenly over centuries.

By late antiquity, the Septuagint tradition had become especially central within Greek-speaking Christianity, while rabbinic Jewish textual culture increasingly centered on Hebrew forms ancestral to the medieval Masoretic Text. Yet the Septuagint's Jewish origin remains essential to understanding what it is: one of antiquity's great Jewish translation achievements before it became a foundational Christian scriptural tradition.

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What This Means for Christian Bibles Today

The connection between the Septuagint and today's different Christian Old Testaments is real, but it needs careful wording. There was no single ancient “Septuagint canon” whose table of contents can simply be compared with a modern Protestant, Catholic, or Orthodox Bible. Ancient Greek biblical manuscripts and later Christian collections contain books and additions beyond the Jewish books eventually represented in the rabbinic Hebrew canon, but their contents are not identical to one another.

Western Catholic tradition eventually received books such as Tobit, Judith, Wisdom, Sirach, Baruch, and 1–2 Maccabees as deuterocanonical. The terminology and the contents are more complicated than the common shorthand suggests; What Are the Apocrypha and Deuterocanonical Books? explains which books different Christian traditions include and why the two terms are not exact synonyms. Protestant Reformers placed the Old Testament books corresponding to the Jewish Hebrew canon in the primary Old Testament collection and treated additional books differently, often grouping them as Apocrypha. Eastern Orthodox traditions preserve a Greek Old Testament inheritance with their own canonical and liturgical history. These differences cannot responsibly be explained by saying that one side simply “kept the Septuagint” while another “removed books.”

The full question of how Jewish and Christian biblical canons developed deserves its own treatment. our guide to how the biblical canon was formed follows that process without collapsing several centuries of debate into a single council or decision.

For readers specifically comparing the two most familiar Western collections, Catholic Bible vs Protestant Bible: Why Are They Different? explains why Catholic Bibles contain 73 books while Protestant Bibles commonly contain 66. For the simpler structural relationship between the Bible's two major Christian divisions, see our companion guide to the Old and New Testaments.

The Septuagint nevertheless remains a living and important text. It is foundational to Eastern Orthodox Old Testament tradition and indispensable to biblical scholarship across confessions. It preserves ancient Jewish interpretations and textual forms, illuminates New Testament quotations and vocabulary, and gives modern readers access to a major branch of Scripture's transmission history.

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