The codex was written in Tiberias about 930, and its vowel points, accents and masoretic apparatus were added by Aaron ben Moses ben Asher, the last of the Tiberian masoretes. It went to Jerusalem, was seized when the Crusaders took the city in 1099 and ransomed by the Jewish community of Fustat in Cairo, where Maimonides consulted it and declared it the manuscript he relied on. It reached Aleppo late in the fourteenth century and stayed there for about six hundred years, kept in an iron chest in the Great Synagogue and shown to almost nobody.
In December 1947, after the United Nations partition vote, the synagogue was burned in a riot. The codex survived, in fragments and in private hands, and was brought to Israel in 1958 by way of a Syrian Jewish merchant, Murad Faham. It arrived missing roughly two fifths of its leaves, including almost the whole of the Torah.
What became of those leaves is disputed and remains so. The account long given was that they burned in 1947. Journalism and archival work since have argued that a substantial number survived the fire and disappeared afterwards, whether in Aleppo or after the codex reached Israel, and members of the Aleppo community have said that the manuscript should never have left their keeping at all. Individual leaves have surfaced since. The atlas records the loss, records that the explanation for it is contested, and does not choose between the accounts on a reader's behalf.