Of course the farther back you go, the spottier the available information is. On many planets centuries of historical records lay in physical form, never having been transferred into the collective data banks of the empire they are in. Also there are numerous planets with unexplored ruins just waiting to have an archaeological dig come and uncover them.
Thus I submit the following skill for "History" (removes Science [Archaeology] and Science [History])
History
The History skill incorporates knowing facts about past and recent events and discoveries, researching in historical archives, and on site physical archeological expeditions.
-- Recent (Empire): The history of your native empire going back to just before Y0. You might know facts about some history older than then but the difficulty goes up the older it is (GM's discretion).
Remembering facts about a significant event: Average (8+) History (recent) check (1D x seconds, EDU).
-- Ancient (Empire): The study of ancient civilizations, both techniques of investigation in un-digitized physical archives and excavations of archeological digs..
Combing through historical archives looking for personal accounts of a battle: Hard (10+) History (ancient) (1D x 10 hours, EDU).
Working an archeological dig: Hard (10+) History (ancient) check (1D x 10 Months, EDU).