This is a large copper follis (35mm, 18.5g) from the Byzantine Empire. It was issued under the emperor Justinian I (527-565). It is dated Year 21 of his reign so was minted in 547/8 AD. It was minted in Theoupolis, which ancient Antioch was named at that time. The mint was sophisticated, being divided into different officina that marked their number on the coins they made, The ruins of Antioch/Theoupolis are located near modern Antakya in Turkey on the far west of its border with Syria. It was at a point of conflict over the ages being Greek, Roman, Byzantine, Arab, Byzantine, Crusaders, Arabs and Turks. It is now too close to the Syrian conflict for comfort.
The follis was equivalent to 40 nummi. The large M on the reverse is the old Greek number 40.
Obverse: Helmeted, armoured facing bust holding cruciger and shield, cross to right. The legend shows Justininan’s titles.
Reverse: Large M; Cross above, officina 3 below, regnal year in roman numerals to right, mint name at bottom.
These impressive sized, very old coins survive in large numbers and are readily found at modest prices for a collector who might want to acquire one.