The follis is both a general term for specific types of bronze coinage that circulated during the Late Roman Empire and for bronze coinage of the Byzantine Empire worth 40 nummi.
An AE1 follis of Diocletian, 27 mm
Constantius II as Caesar on an AE3 follis, 18 mm, minted in Heraclea in 325 AD.
Reverses of a follis (or 40 nummi, marked by "M" for "40" in Greek numerals) next to a pentanummium (or 5 nummi, marked by "Є" for "5" in Greek numerals), both of Anastasius.
A Byzantine follis of Constantine VII and Zoe, minted in 914-919 AD. 26 mm.
The fils is a subdivision of currency used in some Arab countries, such as, in modern times, Iraq and Bahrain. The term is a modern retranscription of fals, an early medieval Arab copper coin first pr
Follis
…in 498 AD with the coinage reform of Anastasius, which included a series of bronze denominations with their values marked in Greek numerals. The fals (the name derived from follis) was a bronze coin issued by the Umayyad and Abbasid caliphates beginning in the late 8th century, initially as imitations…
A fals minted in Damascus between 696 and 750. On one side it reads, "There is no god but God"; on the other, "Minted in Damascus".
Fals of al-Ma'mun, AH 219 (834/5 CE), al-Quds (Jerusalem). Under the Umayyads Jerusalem was known by its Roman name Iliya Filastin ("Aelia Palaestina"), but from the time of Caliph al-Ma'mun, it was given the Islamic religious name al-Quds (meaning «holiness» or «sanctity»).
Fals of Mansur ibn Nuh, minted in Bukhara, AH 353 (964 CE), commemorating the Abbasid caliph al-Muti