Mar Rav Ya'akov HaKohen from Nahar Pakod was head of the yeshiva in Pumbedita [(and Rash"b Yuchsin says in Sura)] for 18 years from year 4471 until year 4489, and the Ra'avah counted him as the second of the Geonim [(Tzemach David), and Shada"k page 58b as in year 4496].