About Nathan ben Nachum, 7th Exilarch 'Mar Ukba I'
Exilarch Mar Ukba I ben Nahum beni David was Exilarch (Exilarch [Hebrew: ראש גלות Rosh Galut, Aramaic: ריש גלותא Reish Galuta lit. "head of the exile", Greek: Æchmalotarcha], referring to the leaders of the Diaspora Jewish community following the deportation of the population of Judah into Babylonian exile after the destruction of the kingdom of Judah) at Babylonia between 210 and 240.
See "My Lines"
from Compiler: R. B. Stewart, Evans, GA
( http://homepages.rootsweb.ancestry.com/~cousin/html/index.htm ) -------------------- Mar-Ukba I,
occupation: Exilarch ca 210-240,
son of Nakhum II and nn to: nn
1) Huna II , occupation: Exilarch 240-259 to: N.N.