Kitāb al-Majisṭī كتاب المجسطي Ptolemy بطلميوس
Books One to Six of the Almagest (كتاب المجسطي), an Arabic version of the Μαθηματικῆς σύνταξις of Ptolemy (Claudius Ptolemaeus; c 90-c 168), thought to have been translated by al-Ḥajjāj ibn Yūsuf ibn Maṭar (786-830). This was the most influential and enduring astronomical text to have survived from the ancient world and its Arabic translation had an immense impact on the late antique and medieval world view in both Christian and Islamic lands.