Codex Alexandrinus (British Library, Royal MS 1 D V-VIII)

Codex Alexandrinus, held at the British Library under shelfmark Royal MS 1 D V-VIII, is a primary source of the first order, one of the earliest and most complete surviving manuscripts of the Greek Bible, dated to the fifth century and containing most of the Old and New Testaments along with several additional early Christian texts. As an actual physical manuscript witness, it carries direct textual authority for reconstructing the early transmission history of the biblical text, cited constantly in critical editions and textual scholarship. Like any single ancient manuscript, it preserves one specific textual tradition among several that circulated in antiquity, so its readings are weighed by textual critics alongside other early manuscripts such as Codex Sinaiticus and Codex Vaticanus rather than treated as automatically definitive wherever manuscripts disagree.