Wikipedia
Theodotion (; , gen.: Θεοδοτίωνος; d. ca. AD 200) was a Hellenistic Jewish scholar, perhaps working in Ephesus, who in ca. AD 150 translated the Hebrew Bible into Greek. Whether he was revising the Septuagint, or was working from Hebrew manuscripts that represented a parallel tradition that has not survived, is debated. In the 2nd century Theodotion's text was quoted in the Shepherd of Hermas and in Justin Martyr's Dialogue with Trypho.
His finished version, which filled some lacunae in the Septuagint version of the Book of Jeremiah and Book of Job, formed one column in Origen of Alexandria's Hexapla, ca. AD 240. (The Hexapla, now only extant in fragments, presented six Hebrew and Greek texts side-by-side: two Greek versions, by Aquila and Symmachus, preceding the Septuagint, and Theodotion's version following it, apparently reflecting a contemporary understanding of their historical sequence.)
Theodotion's translation was so widely copied in the Early Christian church that its version of the Book of Daniel virtually superseded the Septuagint's. Jerome (in his preface to Daniel, AD 407) records the rejection of the Septuagint's version of that book in Christian usage. Jerome's preface also mentions that the Hexapla had notations in it, indicating several major differences in content between the Theodotion Daniel and the earlier versions in Greek and Hebrew. However, Theodotion's Daniel is closer to the modern Hebrew Masoretic Text version (the Hebrew text said to have been finalized ca. AD 130), that is the basis for most modern translations. Theodotion's Daniel is also the one embodied in the authorised edition of the Septuagint published by Sixtus V in 1587.
Theodotion's caution in transliterating Hebrew words for plants, animals, vestments and ritual regalia, and words of uncertain meaning, rather than adopting a Greek rendering, gave him a reputation of being "unlearned" among more confident post-Renaissance editors, such as Bernard de Montfaucon.