The Mardin Hoard: Islamic Countermarks on Byzantine Coins, a 1977 79-page paperback, discusses a hoard found in southern Anatolia of c. 13,500 copper coins of which roughly 2,200 had Arabic countermarks. The hoard was bought by Baldwin and Sons of London in 1972 and they allowed it to be studied before is was disbursed. I bought two coins in 1977 that may well have come from that hoard, although I didn't know that at the time. They are interesting because the same countermark is on two coins that were issued many years apart. The coins have been oriented so the countermark is at 12:00. Each countermark is a "w"-shaped symbol, possibly "Lillah" (for "Allah"). The coin on the left is very worn half-follis (with a large "K" for 20-nummia) of Anastasius. It is 27 mm. It is Sear 43, MIBE 52, attributed to 512-518 AD. The coin on the right is Sear 1836, 29 mm, an anonymous Class D follis attributed to Constantine IX, 1042-1055. Even the coin on the right is very worn. Countermarks were generally applied over a short period of time, so we deduce both coins were available to countermark at the same time, so the Anastasius must have been available to countermark after 1042. These two coins alone show the Anastasius was over 500 years old when it was countermarked. But there is more evidence. On page 41 the book notes that other evidence tells us this is one of the latest countermarks among the types found in the hoard and must be attributed to "after 1160 A.D." The Anastasius was minted in 518 at the latest. We cannot claim it was in continuous circulation all the time until it was countermarked, but it was available after 1160. 1160-518 = 642. That is a minimum of 640 years! No wonder it is not in good shape! The authors tell us the coins were almost all very worn and evidence suggests the hoard was from the second half of the thirteenth century. They posit that the countermarked coins were officially acceptable to the Arab authorities for payments of tax, while the others remained current without countermarks [p. 16]. If the hoard is from the second half of the 13th century (after 1250), even the anonymous bronze was already 200 years old (which explains its very worn condition). That makes the Anastasius still currency at least 730 years after it was minted! (1250-518 = 732). This proves that some Byzantine coins of the right size were useable as money for hundreds of years after they were issued. Sometimes, even extremely worn coins can tell a good story.