Muḥammad ibn Jarīr al-Ṭabarī died in Baghdad on the evening of 26 Shawwāl 310, aged about eighty-five, and was buried the next morning in the courtyard of his house — the crowds, Baghdad's chroniclers insist, prayed at the grave for months.
Two of his works became load-bearing walls of the tradition: the Tafsīr, which gathered the whole exegetical inheritance of the first three centuries, and the Tārīkh al-Rusul wa-l-Mulūk, the year-by-year chronicle that is the single most cited source in this database. His care to give each report with its chain — recording variants rather than resolving them — is, at a distance of eleven centuries, the method this project aspires to.
The date is carried by his student Ibn Kāmil and the Baghdad biographers.