(Mediaeval French, almageste, from Arabic: al-Majisti, "the Greatest")
An astronomical work compiled in Greek around 140 by Ptolemy of Alexandria. It was translated into Arabic in the 9th century and only became known in Europe when it was translated into Latin in the 12th century.
In 13 volumes, the Almagest covers all of ancient astronomy, including a detailed description of the Ptolemaic System, the ancient worldview which placed the Earth at the center of the solar system (since replaced by the Copernican System). Also included in the Almagest is a star catalogue listing positions and magnitudes for 1022 stars (naked-eye stars of magnitudes 1 to 6).