Auction houses suggest a few different rulers and denominations for these coins, in varying strike quality, but generally all date them to the fourth century B.C., in Asia Minor. These coins often show a Persian king kneeling or running, advancing right.
Roma Numismatics offered a bronze example in a Sept. 30, 2015, auction apparently issued under Memnon of Rhodos. This piece has a dark patina and was graded Very Fine by the auction firm and hammered for £320 (about $485 U.S.).
The admiral of the Persian navy, Memnon of Rhodos, was charged by Darius to halt the Macedonian advance on Asia Minor under Alexander the Great. Although Memnon took Ephesos, he was defeated decisively in 334 B.C. at the River Granicos in Mysia by Alexander who had crossed the Hellespont earlier that year.
A circa 334 B.C. piece bearing the apparent map reverse and attributed to Memnon, a silver 2.5-sigloi coin, was offered in the New York Sale in 2002 and then again in Dmitry Markov’s auction No. 99 in 2003, but it is in rough condition and failed to sell in both appearances.
Another example, a silver tetradrachm in Extremely Fine condition, sold in Hess-Divo’s Nov. 17, 2015, auction for a hammer price of 15,000 Swiss francs (about $14,889 U.S.)
The better condition allows the topographical nature of the reported map reverse to be more apparent. Given the use of coins as a medium of communication in ancient times, the usefulness of such a coin, especially when clans and peoples were often at war, is obvious.