اقتباس:

What are the oldest manuscripts we have of Josephus' works?
The oldest manuscripts of the works of Josephus in their original language of Greek date to the tenth and eleventh centuries. Portions of the works are also quoted in earlier manuscripts by other authors, particularly Eusebius (fourth century). There are also versions in other languages, notably a Latin translation made about the fifth century. These are all codexes, bound books, not scrolls.

As with all ancient texts, variations appear among the manuscripts due to inaccuracies in copying. The two manuscripts considered to have the best texts for the Jewish War are the Codex Parisinus Graecus and the Codex Ambrosianus, both dating from circa 900-1000 CE. The Jewish Antiquities, because of its length, was transmitted in two parts; the best texts for the first half (Antiquities Books 1 to 10) are Codex Regius Parisinus (fourteenth century) and Codex Oxoniensis (fifteenth century); the best texts for the second half (Antiquities Books 11 to 20) are Codex Palatinus (ninth or tenth century) and Codex Ambrosianus; the latter are also the preferred authorities for the Life . The only manuscript for Against Apion is Codex Laurentius, from the eleventh century, which has a large gap in Book II that must be filled by the old Latin version.

Numerous translations of these manuscripts have appeared over the years, and exploded in number after the invention of the printing press; the first printed edition dates from 1470. An important printed Greek edition, now called the Editio Princeps, was published by Johannes Froben in Basel in 1544, which seems to use a manuscript different from those known. Using the oldest manuscripts to try to determine the original text, Benedict Niese from 1887 to 1889 published a six volume Greek edition with full notes as to the variant readings; this is the text used for the English translations of both the Loeb Library edition and the new Brill Josephus Project, although the translators at times prefer alternate readings as the best ones against Niese's choices. The very popular Whiston translation, first published in 1737, is unfortunately not based on as fine a text, and so careful readers will find differences between the Whiston version and more modern translations.

References:

The Jewish War, Books I-II, Introduction to the Loeb Edition by H. St. J. Thackeray (Cambridge, MA, 1927)
Jewish Antiquities, Books I-IV, Introduction to the Loeb Edition by H. St. J. Thackeray (Cambridge, MA, 1930)
Jewish Antiquities, Books IX-XI, Prefatory Note to the Loeb Edition by Ralph Marcus (Cambridge, MA, 1937)
The Brill Josephus Project, Series Preface by Steve Mason (appearing in each volume) (Leiden, Brill, 1999)
Rezeptionsgeschichtliche und textkritishe Untersuchungen zu Flavius Josephus, Heinz Schreckenberg
(Leiden, Brill, 1977)