Robert Fleischer, Hellenistic Royal Iconography on Coins

Why focus on coins to study Hellenistic royal iconography? Certainly they are small and often not in a good state of preservation; details are not easily visible. But coins have some important advantages. First, they are subject to control by officials, and, if they come from the capitals of the empires, it is very likely that they conform to a picture of the king accepted by the royal court, if not invented there. Sculptured portraits, on the contrary, often show a very free interpretation of the king’s portrait, depending upon intentions of the patron. There are only very occasionally problems in identifying kings’ portraits on coins, but in the case of heads from statues identification is often very problematic. When heads have been identified, it was done nearly always with the help of the portraits on the coins. Finally, these portraits not only allow us to follow the appearance of single rulers and of dynasties, sometimes over long periods. They reveal changes as well in the way a ruler presented himself during his reign; they also reveal the continuation or the changes from father to son, and sometimes the relations between the portraits of kings of different dynasties.

Robert Fleischer, Hellenistic Royal Iconography on Coins
(In Studies in Hellenistic Civilization, Vol. VII – Aspects of Hellenistic Kingship, p. 28.
Aarhus University Press, 1996)