The Kitāb al-Ṭabaqāt al-Kabīr ( Biography of Muḥammad, His Companions and the Successors up to the Year 230 of the Hijra ) by Ibn Saʿd (d. 230 A.H./845 C.E.) is the earliest extant biographical dictionary on the life of the Prophet and the early generations of Muslims. It is one of the most important historical works about the first centuries of Muslim society in Arabic. This classic Brill edition was supervised by Eduard Sachau and was originally titled Biographien Muhammeds, seiner Gefährten und der späteren Träger des Islams bis zum Jahre 230 der Flucht . This edition was originally published between 1904 and 1940. Contributing editors Carl Brockelmann, Josef Horovitz, Julius Lippert, Bruno Meissner, Eugen Mittwoch, Friedrich Schwally, Karl Vilhelm Zetterstéen.