This is the earliest Arab-Byzantine coin which was minted during the era of the early caliphate (Rashidun Caliphate) between 638-647 CE. This folles is an imitated coin of contemporary Byzantine circulating issues of Heraclius struck in Cyprus. It has a frozen regnal year of 17 (627 CE). This coin is classified as type B which could have been struck circa 640 CE the earliest and not more than 645 CE. Umar Ibn al-Khattab led the Muslim community from 634 - 644 CE.
Obverse
Three standing imperial figures, Heraclius in centre to his right Martina ( his niece-bride ) and to his left Heraclius Constantine ( his son ), wearing chlamys and crown with cross, holding globus crucigers.
( Take note that the figure on the left is Martina and not Heraklonas due to her feminine silhoutte, flared robe and tall crown with pendilia/flowing hair locks falling to her shoulders)
Reverse
Uncial letter M, to left downwards ANNO to right downwards regnal year XЧII ( = year 17 or 627 CE) between limbs of M officina letter Γ( third officina ) above Heraclian monogram hR and in exergue mint-signature (ΚΥΠΡ')
After the battle of Yarmuk in 636 CE, Syria was taken over from Byzantine power.
To keep economy activities in the area, imitations of coin were made reflecting Heraclius and Constans II. For example, coins from Emperor Constans II, who succeeded after the Battle of Yarmuk, were found in Syria and Cyprus long after the Byzantine Empire had supposedly lost control. This indicates that coins might have been struck in Cyprus for use in Islamic provinces. Yet due to abundance of this coins were discovered mainly in Syria and rarely in Cyprus hypothesized that they were most probably struck in an area that is modern day Syria; a plethora of imitations were put into circulation during the early days when the Arabs controlled the region; especially folles bearing the Cypriot mint-signature were singled out for copying in preference to other issues. The prototype coin most likely from below Official Byzantine Heraclius coin which has weight 5gm and diam of 26mm which was produced between 626-627 CE. These coins circulated in vast quantities across the Eastern Mediterranean, Syria and Palestine during the final decades of Byzantine rule.

Additionally, coins with the Cyprus mint-mark were likely produced in Syria, imitating earlier issues. This raises several possibilities: the coins might be unofficial imitations, or there could have been a mint in Cyprus under Islamic control producing coins that looked authentic. Alternatively, Constantinople might have been producing coins specifically for export to Cyprus and Syria.
But I believed the first hypothesis could be the reason. After the victory at the Battle of Yarmouk (636 CE) and the fall of Jerusalem ( 637-638CE) under the Caliph Umar Ibn Al Khattab, the region was cut off from official Byzantine imperial mints like Constantinople. To keep daily local commerce functioning, regional mints across Bilad al-Sham (Syria/Levant) and adjacent regions continued producing low-denomination copper coins by copying familiar Byzantine issues that locals already trusted.Rather than updating the regnal year, local die-engravers copied existing coins directly—mechanically preserving the "Year 17" inscription as a static or "frozen" design element. Leading numismatists (such as Clive Foss and Tony Goodwin) classify these early "Class B" pseudo-Byzantine / Arab-Byzantine imitations as having entered production circa 640 CE (and continuing through the 640s and 650s CE), making a date between 636 CE and 645 CE ideal for the earliest wave of this series.
This coin has a peculiar shape which has an elliptical flan due to cutting the angular corners. This coin could be struck a cut coin of earlier bigger Byzantine follis with 2 corners trimmed to give it oval shape. The larger follis could be from 11gm weight.
The name “copper” originates from the Roman era when the metal was primarily mined on the island of Cyprus. It was initially called aes cyprium (metal of Cyprus), which was later shortened to cuprum in Latin. This evolved into the Old English “coper” and eventually became “copper” around 1530.
Obverse :
Three standing imperial figures, Heraclius in centre to his right Martina ( his niece-bride ) and to his left Heraclius Constantine ( his son ), wearing chlamys and crown with cross, holding globus crucigers.
Reverse :
Uncial letter M, to left downwards ANNO to right downwards regnal year XЧII ( = ear 17 or 627 CE) between limbs of M officina letter Γ( third officina ) above Heraclian monogram hR and in exergue mint-signature (ΚΥΠΡ')
Weight : 0.59 gm
Dim : 29 mm
Date : Frozen 17 Heraclius regnal year ( 627 CE) but imitated circa 640 CE
Rarity :
Denom : follis
Material : Copper
Reference : pg 13-16 (Arab Byzantine Coinage)
pg 22-24 ( Arab Byzantine Coins - Clive Foss)