According to the Letter of Aristeas, an ancient document, 72 Jewish scholars were said to have been selected to translate the into Greek in the 3rd century BCE, during the reign of Ptolemy II Philadelphus. These scholars, six from each tribe of Israel, are said to have worked independently, yet their translations were reportedly found to be identical when compared.
The Letter of Aristeas is often regarded as a pseudepigraphon, that is, a text attributed to an author who is not its real author. It was probably written in the 2nd century BCE, well after the events it describes.
Although the letter is a work of propaganda of Alexandrian Judaism and reflects the spirit of its time, it is difficult to regard it as a reliable historical source for the precise details it reports, such as the exact number of translators or the independent nature of their translations.
In summary, the Letter of Aristeas is a valuable source for understanding the cultural and religious context of the time, but it should not be taken as an exact historical account.