Codex Sinaiticus (London, Brit. Libr., Add. 43725; Gregory-Aland no. א (Aleph) or 01) is a 4th century uncial manuscript of the Greek Bible, written between 330–350. Originally containing the whole of both Testaments, only portions of the Greek Old Testament or Septuagint survive along with a complete New Testament, the Epistle of Barnabas and portions of The Shepherd of Hermas. Along with Codex Vaticanus, Codex Sinaiticus is one of the most valuable manuscripts for Textual criticism of the Greek New Testament, as well as the Septuagint.
The entire codex consists of 346 1/2 folios, written in four columns. Of these, 199 belong to the Old Testament and 147 1/2 belong to the New Testament, along with two other books, the Epistle of Barnabas and part of The Shepherd of Hermas. The books of the New Testament are arranged in this order: the four Gospels, the epistles of Paul, the Acts of the Apostles, the General Epistles, Revelation.
Of its prior history, little is known. It is speculated to have been written in Egypt and it is sometimes associated with the 50 copies of the scriptures commissioned by Roman Emperor Constantine after his conversion to Christianity
A paleographical study at the British Museum in 1938 found that the text had undergone several corrections. The first corrections were done by several scribes before the manuscript left the scriptorium. In the sixth or seventh century many alterations were made, which, according to a colophon at the end of the book of Esdras and Esther states, that the source of these alterations was "a very ancient manuscript that had been corrected by the hand of the holy martyr Pamphylus". From this is concluded, that it had been in Caesarea Palaestina in the 6th or 7th centuries. Uncorrected is the pervasive iotacism, especially of the ει diphthong.
Codex Sinaiticus was found by Constantin von Tischendorf on his third visit to the Monastery of Saint Catherine, on Mount Sinai in Egypt, in 1859. The first two trips had yielded parts of the Old Testament, some found in a basket of manuscripts pieces, which Tischendorf was told by a librarian that "they were rubbish which was to be destroyed by burning it in the ovens of the monastery". The emperor Alexander II of Russia sent him to search for manuscripts, which he was convinced were still to be found in the Sinai monastery. In May 1975 during restoration work, the monks of St. Catherine's monastery at Sinai discovered a room under the St. George chapel which contained many parchment fragments. Among these fragments, twelve missing leaves from the Sinaiticus Old Testament were found.
The story of how von Tischendorf found the manuscript, which contained most of the Old Testament and all of the New Testament, has all the interest of a romance. Von Tischendorf reached the monastery on January 31; but his inquiries appeared to be fruitless. On February 4, he had resolved to return home without having gained his object.
- On the afternoon of this day I was taking a walk with the steward of the convent in the neighbourhood, and as we returned, towards sunset, he begged me to take some refreshment with him in his cell. Scarcely had he entered the room, when, resuming our former subject of conversation, he said: "And I, too, have read a Septuagint"--i.e. a copy of the Greek translation made by the Seventy. And so saying, he took down from the corner of the room a bulky kind of volume, wrapped up in a red cloth, and laid it before me. I unrolled the cover, and discovered, to my great surprise, not only those very fragments which, fifteen years before, I had taken out of the basket, but also other parts of the Old Testament, the New Testament complete, and, in addition, the Epistle of Barnabas and a part of the Pastor of Hermas.
After some negotiations, he obtained possession of this precious fragment, and conveyed it to Emperor Alexander, who fully appreciated its importance, and caused it to be published as nearly as possible in facsimile, so as to exhibit correctly the ancient handwriting. However, the tsar sent 9000 roubles to the monastery as a compensation.Regarding Tischendorf's role in the transfer to Leningrad, there are several views. Although when parts of Genesis and Book of Numbers were later found in the binding of other books, they were amicably sent to Tischendorf, the Codex is currently regarded by the monastery as having been stolen, a view hotly contested by several scholars in Europe. In a more neutral spirit, New Testament scholar Bruce Metzger writes: "Certain aspects of the negotiations leading to the transfer of the codex to the Czar's possession are open to an interpretation that reflects adversely on Tischendorf's candour and good faith with the monks at St. Catherine's. For a recent account intended to exculpate him of blame, see Erhard Lauch's article 'Nichts gegen Tischendorf' in Bekenntnis zur Kirche: Frestabe für Ernst Sommerlath zum 70. Geburtstag (Berlin, c. 1961); for an account that includes a hitherto unknown receipt given by Tischendorf to the authorities at the monastery promising to return the manuscript from St. Petersburg 'to the Holy Confraternity of Sinai at its earliest request'.<ref>See Ihor Šev
- Bruce A. Metzger, the Text of the New Testament, it's Transmission, Corruption and Restoration, Oxford University Press, 1992, p46.
- Skeat, T. C. "The Last Chapter in the History of the Codex Sinaiticus." Novum Testamentum. Vol. 42, Fasc. 3, Jul., 2000. p. 313
- See Constantin von Tischendorf, The Discovery of the Sinaitic Manuscript, Extract from Constantin von Tischendorf, When Were Our Gospels Written? An Argument by Constantine Tischendorf. With a Narrative of the Discovery of the Sinaitic Manuscript [New York: American Tract Society, 1866].