Codex Alexandrinus

One of the three earliest and most complete Greek Bible manuscripts, providing the best early witness to the book of Revelation and 1–2 Clement, and serving as a key example of the mixed text-types that circulated in 5th-century Christianity.

Codex Alexandrinus, designated A or 02 in the Gregory-Aland numbering system, is a 5th-century Greek Bible manuscript housed in the British Library in London. Together with Codex Sinaiticus (4th century) and Codex Vaticanus (4th century), it forms the trio of great uncial codices that are the most important manuscript witnesses to the text of the Greek Bible. While somewhat later than its two companions, Alexandrinus contributes uniquely important textual evidence, particularly for the book of Revelation, 1 and 2 Clement, and the Psalms of Solomon.

The codex's name derives from a note in the manuscript stating it was written by the hand of Thecla, a noble Egyptian woman, which tradition associates with Alexandria. The manuscript was brought from Alexandria to Constantinople by Cyril Lucar, who served as Patriarch of Alexandria before becoming Ecumenical Patriarch of Constantinople. In 1627, Lucar presented the codex as a gift to King Charles I of England through Sir Thomas Roe, the English ambassador to the Ottoman court. It was initially placed in the Royal Library and later transferred to the British Museum (now British Library) when the royal collections were acquired by the nation in 1757.

The codex consists of 773 surviving leaves of fine vellum, each measuring approximately 32 by 26 centimeters, with the text arranged in two columns per page. It was written by at least two scribes in a careful uncial hand. The complete codex originally contained the entire Greek Bible plus additional texts. The Old Testament section preserves most of the Septuagint, including the deuterocanonical/apocryphal books. The New Testament section originally included all 27 canonical books, though some pages have been lost: most of Matthew (chapters 1:1–25:6), two leaves of John (6:50–8:52), and three leaves of 2 Corinthians (4:13–12:6).

After Revelation, the codex includes two texts not found in the later canon: the First Epistle of Clement (1 Clement) and, in a fragmentary state, the Second Epistle of Clement (2 Clement). These are the earliest Greek manuscripts of 1 Clement, an important letter from the church at Rome to the church at Corinth, traditionally dated to around 96 CE. The presence of these texts after Revelation indicates that some 5th-century communities still regarded them as Scripture or near-Scripture. Following 2 Clement, the table of contents lists the Psalms of Solomon, an apocryphal collection, but the actual text pages have been lost.

Textually, Codex Alexandrinus presents a mixed picture. In the Gospels, its text is largely Byzantine — that is, it agrees more often with the later majority of manuscripts rather than with the older Alexandrian tradition represented by Sinaiticus and Vaticanus. This makes it the earliest major witness to the Byzantine text-type in the Gospels. However, in Acts, the Epistles, and Revelation, Alexandrinus shifts to an Alexandrian text, agreeing much more frequently with Sinaiticus and Vaticanus. This mixed character suggests that the codex was copied from different exemplars for different sections of the Bible.

For the book of Revelation, Codex Alexandrinus is widely regarded as the single best manuscript witness. Codex Sinaiticus also contains Revelation, but with a noticeably different (and somewhat inferior) text. Vaticanus lacks Revelation entirely (in its original hand). Because Revelation circulated separately from the rest of the New Testament in many early manuscript traditions, the textual evidence for this book is different from the evidence for the Gospels and Epistles. Alexandrinus fills a critical gap.

The manuscript's physical features are notable. The text includes decorative elements: large initial letters at the beginnings of sections, colophons at the ends of books, and ekthesis (the first line of a new section projected into the margin). These features provide important evidence for the development of book design and the organization of the biblical text in late antiquity. The Eusebian canon tables, a reference system correlating parallel passages across the four Gospels invented by Eusebius of Caesarea in the early 4th century, are present in the Gospel section, indicating that this system was standard by the 5th century.

The codex has been digitized in its entirety by the British Library, and high-resolution images are freely available online, allowing scholars worldwide to study its text and physical characteristics.

• 5th-century Greek Bible, one of the three great uncial codices alongside Sinaiticus and Vaticanus
• 773 surviving leaves containing most of the Septuagint, New Testament, 1–2 Clement, and originally the Psalms of Solomon
• Best manuscript witness to the book of Revelation, filling a gap left by Vaticanus
• Mixed text-type: Byzantine in the Gospels, Alexandrian in Acts, Epistles, and Revelation
• Earliest Greek manuscript of 1 Clement, the important late 1st-century letter from Rome to Corinth
• Gifted to King Charles I of England in 1627 by Patriarch Cyril Lucar of Constantinople
• Eusebian canon tables present, documenting the standard Gospel cross-reference system
• Some pages lost: most of Matthew, portions of John and 2 Corinthians

Codex Alexandrinus is particularly significant for the book of Revelation, providing the earliest high-quality complete text of John's apocalyptic vision. The transmission of Revelation followed a different path from the rest of the New Testament, and Alexandrinus anchors the textual tradition for this most dramatic of biblical books. From the opening — "The Revelation of Jesus Christ, which God gave unto him" (Revelation 1:1) — to the closing — "The grace of our Lord Jesus Christ be with you all. Amen" (Revelation 22:21) — Alexandrinus preserves the text with remarkable care. The inclusion of 1 Clement after Revelation illuminates the early Christian understanding of the biblical canon. That a 5th-century Bible manuscript included Clement's letter alongside the apostolic writings shows that the boundaries of the New Testament were still somewhat fluid centuries after the books were composed. Clement's letter, with its emphasis on order, humility, and the example of Old Testament figures, represents the earliest non-canonical Christian text of known date and authorship. The Byzantine text-type in the Gospels preserved by Alexandrinus is significant because this text tradition, though generally considered secondary by modern text critics, became the dominant form of the Greek New Testament in the medieval church and was the basis for the Textus Receptus, which in turn underlies the King James Version. Alexandrinus is thus the earliest large manuscript witness to the text that billions of Christians have read for centuries.