This post is part of an ongoing series on the Scriptures of Saint Patrick of Ireland.
During the course of the Middle Ages two groups of Latin Bibles circulated in the Western world, the Vetus Latina and Vulgate versions. The Vetus Latina (“old Latin”) is a family of locally made Latin translations of both the Old and New Testaments. Two major strands of the Vetus Latina arose almost simultaneously between 150 and 200 CE, one in Roman Africa and another in Europe. In addition to these “original” Old Latin translations, there may have been a fourth-century Italian revision of the Vetus Latina prior to Jerome’s cooption and revision of the text.
The Old Latin translations of the Old Testament depended on various Septuagint translations of the Hebrew Bible—the Septuagint did not exist in pandect form before the third or fourth century—thus making much of the Latin Old Testament a translation of a translation. Translations of the New Testament into Latin were also made before 200 CE and continued quite steadily even after the publication of the Vulgate. Although there are more than fifty extant Vetus Latina manuscripts (thirty-two which contain at least portions of the Gospels), there exists no complete Old Latin copy of the Bible. Some of the oldest, fullest, and (thereby) most important Vetus Latina codices are Codex Vercellensis (a), Codex Veronensis (b), Codex Palatinus (e), and Codex Bobiensis (k).
In addition to these sources, the Vetus Latina text is reflected in patristic and medieval citations, mixed-type Biblical manuscripts (more on this below), glosses and additions to Jerome’s translation, liturgical sources (the most famous of these being “Gloria in excelsis Deo” from Luke 2:14), and sequences of capitula and tituli. Above all, it must be recognized that the often heterogeneous Vetus Latina was the Bible of the Latin Church Fathers and many medieval Christians as well. And, as one might expect, this heterogeneity led to concerns about the integrity of the text, for, as Jerome said, “tot sunt (exemplaria) paene quot codices” (“There are almost as many different translations as there are manuscripts.”).
 Van Liere, 83. For a discussion of the earliest manuscripts of the Latin Bible, see Patrick McGurk. “The oldest manuscripts of the Latin Bible.” The Early Medieval Bible: Its production, decoration and use. Edited by Richard Gameson. Cambridge: Cambridge University Press, 1994. 1-23.
 Pierre-Maurice Bogaert. “The Latin Bible.” Edited by James Carleton Paget and Joachim Schaper. The New Cambridge History of the Bible: Volume 1: From Beginnings to 600. Cambridge: Cambridge University Press, 2012. 505-506. Kenyon, 239. C.S.C. Williams. “The History of the Text and Canon of the New Testament to Jerome.” Edited by G.W.H. Lampe. The Cambridge History of the Bible: Volume 2: The West from the Fathers to the Reformation. Cambridge: Cambridge University Press, 1969. 37. The Vetus Latina almost certainly did not arise in Rome, where the church used Greek for its liturgy until the early third century and was preceeded by Milan in its switch to the vernacular Latin liturgy. See Williams, 37.
 Frederic Kenyon. Our Bible and the Ancient Manuscripts. Revised by A.W. Adams. New York: Harper and Row, 1962. 239.
 Bogaert, 509. Boynton and Reilly, 2. Occasional agreements between Vetus Latina texts and the (Hebrew) Masoretic text—over against the standard Septuagint form—suggest that some Old Latin translations of Old Testament writings relied upon a Hebrew exemplar.
 Bogaert. 509. See especially fifth-century Codex Bezae Cantabrigensis, where Latin and Greek versions of the Gospels and Acts appear side-by-side.
 Kurt Aland and Barbara Aland. The Text of the New Testament: An Introduction to the Critical Editions and to the Theory and Practice of Modern Textual Criticism, Second Edition. Translated by Erroll F. Rhodes. Grand Rapids: Eerdmans, 1989. 187. Bruce M. Metzger. The Text of the New Testament: Its Transmission, Corruption, and Restoration, Third Edition. New York: Oxford University Press, 1992. 72. Van Liere, 82. See also Nestle-Aland 26, 712-716. Aland notes that we may expect extant manuscripts to represent but a small portion of the number that originally existed. For insights into the manuscript characteristics of early Latin manuscripts, see E. A. Lowe, “Some Facts about Our Oldest Latin Manuscripts.” The Classical Quarterly 19, 3/4 (1925): 197-208.
 Aland and Aland, 189.
 Boegaert, 507-508.
 Ascertaining which Patristic citations are authentic Vetus Latina traditions must be considered in light of several risks, writes Pierre-Maurice Bogaert, who outlines the three following concerns: “(i) The normalization in accordance with the text which later became the Vulgate affected its transmission very early and considerably later too. (ii) The text reproduced at the head of a commentary or section of commentary (lemma), might have been added if it was not given in the archetype; it might have been normalized in further use, due to its easy location. The faithfulness of lemmata may be judged through reference to a biblical text correctly cited or explained within the commentary itself, therefore less easily detected and corrected. (iii) The identification of quotes given by editors is sometimes incorrect, since they thought they could be found in Vulgate concordances, whereas the vast majority of the fathers did not know or rarely used Jerome’s traditions from the Hebrew. To identify difficult cases especially, one must attempt a Greek retroversion, and search the Septuagint concordances.” See Bogaert, 507.
 Aland and Aland, 187.