Rav Netura'i Gaon bar Mar Rav Nechemya ruled in Pumbedita around year 4470 [(Tzemach David). After many ruled, Rav Netrona'i, etc. ruled in year 1000 (meaning according to the Seleucid era.

Thus it is year 4448, but according to Tzemach David, Mar Huna ruled in year 1000. And Rav Netura'i ruled in year 4470, and thus it should read, in my opinion [in Rash"b regarding Rav Netrona'i] 1000 and 20). It is known that Mar Rav Yanuka, son-in-law of David, signed on his house. The Exilarch asserted authority over the Rabbis and they fled to their yeshiva (Rash"b in Yuchsin)].