Written in Aramaic in 987, it is a history of the mesorah from Sinai until his day. Commentary and explanations included. Translated by Rabbi Nosson Dovid Rabinowich.
Rav Sherira Gaon: was the head of yeshiva in Pumbeditha. He wrote the Iggeret Rav Sherira Gaon, a comprehensive history of the composition of the Talmud One of the most prominent Ge'onim of his period.