The Aleppo Codex (כֶּתֶר אֲרָם צוֹבָא, romanized: Keṯer ʾĂrām-Ṣōḇāʾ, lit. 'Crown of Aleppo') is a medieval bound manuscript of the Hebrew Bible. The codex was written in the city of Tiberias in the tenth century CE (circa 920) under the rule of the Abbasid Caliphate, and was endorsed for its accuracy by Maimonides. Together with the Leningrad Codex, it contains the Ben-Asher masoretic tradition.
The codex was kept for five centuries in the Central Synagogue of Aleppo, until the synagogue was torched during anti-Jewish riots in 1947. The fate of the codex during the subsequent decade is unclear: when it resurfaced in Israel in 1958, roughly 40% of the manuscript—including the majority of the Torah section—was missing, and only two additional leaves have been recovered since then. The original supposition that the missing pages were destroyed in the synagogue fire has increasingly been challenged, fueling speculation that they survive in private hands.
The portion of the codex that is accounted for is housed in the Shrine of the Book at the Israel Museum.
The Hebrew name is Keṯer ʾĂrām-Ṣōḇāʾ, translated as "Crown of Aleppo": keter means "crown", and Aram-Zobah was a not-yet-identified biblical city in modern Syria, whose name was applied from the 11th century onward by some Rabbinical sources and Syrian Jews, to the area of Aleppo in Syria. The term keter is a translation of Arabic taj, originally Persian taj ("crown"); the codex was called "al-Taj" by locals until the modern period. In Arabic the term taj was used mostly as a stock superlative title (Muslim caliphs did not wear crowns) and applied liberally to model codices, but it lost this sense when translated into Hebrew as keter, which has only the literal sense of "crown".
The Karaite Jewish community of Jerusalem purchased the codex about a hundred years after it was made. When the Crusaders conquered Jerusalem in 1099, the synagogue was plundered and the codex was held for a high ransom, which was paid with money coming from Egypt, leading to the codex being transferred there.