The Septuagint or LXX (from the Latin: septuāgintā literally "seventy"; sometimes called the Greek Old Testament) is the earliest extant Greek translation of the Old Testament from the original Hebrew. It is estimated that the first five books of the Old Testament, known as the Torah or Pentateuch, were translated in the mid-3rd century BCE and the remaining texts were translated in the 2nd century BCE. Under Christian auspices, the Septuagint includes the Hebrew Bible as well as the deuterocanonical books of the Christian Old Testament. Considered the primary Greek translation of the Old Testament, it is quoted a number of times in the New Testament, particularly in Pauline epistles, by the Apostolic Fathers, and later by the Greek Church Fathers.
The full title in Ancient Greek: Ἡ μετάφρασις τῶν Ἑβδομήκοντα, literally "The Translation of the Seventy", derives from the traditional story recorded in the Letter of Aristeas that the Septuagint was translated at the request of Ptolemy II by 70 or 72 Jewish scholars (6 from each of the 12 tribes of Israel) who independently translated identical versions of the entire Hebrew canon. Subsequently, the Greek translation was in circulation among the Alexandrian Jews who were fluent in Greek, the common language in Egypt at the time, but not in Hebrew. Separated from the Hebrew canon in Rabbinic Judaism, translations of the Torah into Greek by early Jewish rabbis have survived as rare fragments only.
The Septuagint should not be confused with other Greek versions of the Old Testament, most of which did not survive except as fragments (some parts of these being known from Origen's Hexapla, a comparison of six translations in adjacent columns, now almost wholly lost). Of these, the most important are those by Aquila, Symmachus, and Theodotion.
The Septuagint derives its name from the Latin versio septuaginta interpretum, "translation of the seventy interpreters", Greek: ἡ μετάφρασις τῶν ἑβδομήκοντα, hē metáphrasis tōn hebdomḗkonta, "translation of the seventy". However, it was not until the time of Augustine of Hippo (354–430 CE) that the Greek translation of the Jewish scriptures came to be called by the Latin term Septuaginta. The Roman numeral LXX (seventy) is commonly used as an abbreviation, as are or G.