Aquila of Sinope
Only fragments of this translation have survived in what remains of fragmentary documents taken from the 1st and 2nd Book of Kings, and from the Psalms, found in the old Cairo Geniza in Fostat (Egypt), while excerpts taken from the Hexapla written in the glosses of certain manuscripts of the Septuagint were collected earlier and published by Frederick Field in his momentous work, Origenis Hexaplorum quæ Supersunt, Oxford, 1875. So, too, Aquila's Aramaic Targum (translation) of the Pentateuch has been preserved by Jews unto this very day, and is appended to most printed Hebrew texts of the Five Books of Moses. Epiphanius (De Ponderibus et Mensuris, chap. xiii-xvi.; ed. Migne, ii. 259-264) preserves a tradition that he was a kinsman of the Emperor Hadrian, who employed him in rebuilding Jerusalem (as Aelia Capitolina), and that Aquila was converted to Christianity but, on being reproved for practicing astrology, 'apostatized' to Judaism. He is said also to have been a disciple of Rabbi Akiva (d. ca. 132 CE).
In Jewish writings he is referred to as עקילס (Aquilas), although he is also known by its Hebrew corruption, Onkelos. Aquila's version is said to have been used in place of the Septuagint in Greek-speaking synagogues. The Christians generally disliked it, alleging that it rendered the Messianic passages incorrectly, but Jerome and Origen speak in its praise. Origen incorporated it in his Hexapla.
It was thought that this was the only copy extant, but in 1897 fragments of two codices were brought to the Cambridge University Library. These have been published: the fragments AqBurkitt containing 1 Kings xx. 7-17; 2 Kings xxiii. 12-27 by F. C. Burkitt in 1897,those containing parts of Psalms xc.-ciii. (signed as AqTaylor) by C. Taylor in 1899. See F. C. Burkitt's article in the Jewish Encyclopaedia.
Early Rabbinic reference to Aquila's conversion
The following story is related about Aquila’s conversion in the old Hebrew classic, Midrash Rabba (Exodus Rabba 30:9): “Once, Aquilas said to Hadrian the king, ‘I wish to convert and to become one of Israel.’ He answered him, ‘You are seeking [to join] that nation? How have I despised it! How have I killed it; the most downtrodden of the nations you are asking to join!? What have you seen in them that you wish to be made a proselyte?’ He replied, ‘The smallest of them knows how the Holy One, blessed be He, created the universe; what was created on the first day and what was created on the second day, and how many [years] have passed since the universe was created, and by what [things] the world is sustained. Moreover, their Divine Law is the truth.’ He said to him, ‘Go and study their Divine Law, but do not be circumcised.’ Aquilas then said to him, ‘Even the wisest man in your kingdom, and an elder who is aged one-hundred, cannot study their Divine Law if he isn’t circumcised, for thus is it written: He makes known his words unto Jacob, even his precepts and judgments unto Israel. He has not done the like of which to any other nation (Ps. 147:19-20). Unto whom, then, [has he done it]? Unto the sons of Israel!’”
- Epiphanius' "Treatise on Weights and Measures" - Syriac Version (ed. James Elmer Dean), Chicago University Press c1935, pp. 30-31. Click to see online translation of Epiphanius' Treatise on Weights and Measures