The Shahnameh (The Book of Kings) is an epic poem written circa 1000 A.D. It traces the history of Greater Iran. The game of Nard is mentioned but its description is not very clear.
Since the 14th century, copies of the Shahnameh are illustrated and allow to see a resemblance to backgammon. Among these illustrated copies, some scenes suggest that the starting position was the same as today.
This folio from 1300/1330 (Iran or Iraq) shows a game already begun. The vizir Buzurjmihr hides 3 red pieces with his hand.
On thes folio from 1500 (sultanate India), the vizir Buzurjmihr has moved 5 white pieces from their starting positions whereas the Black player has only moved 2. The Black player is behind in race because one the 2 pieces he moved was hit.
This folio from 1525 (Turkey) shows the starting position but only the black pieces are depicted.