Originally the name for a military pursor 's leather purse, later the term for money of account, and a denomination during the Tetrarchy and the Byzantine Empire.

Follis of the Tetrarchy A.D. 293 - 306

In 293, Diocletian introduced the follis (plural: folles) a new larger denomination with a laureate portrait to replace the radiate antoninianus (or aurelianianus). Diocletian 's new denomination had a copper core, and a 5% silver plate, the same as the radiates it replaced, but was c. 28 - 32 mm diameter, on a consistent weight standard of 10.75 grams. The follis was initially tariffed at 5 denarii communes (also the same as the radiates it replaced), but was later devalued to 12.5 d.c. and then to 25 d.c. Smaller fraction were struck with a radiate portrait, called "post-reform radiates." On the tetrarchic folles, portraits of the various emperors were highly stylized and usually indistinguishable. Often the emperor depicted can only be determined by the obverse legend. The most common reverse type had the legend GENIO POPVLI ROMANI, and depicted the Genius (spirit) of the Roman people standing making a sacrifice. In 301, the western mints struck a common type with the legend Sacra Moneta, and depicting Moneta standing holding scales and a cornucopia. The large folles of the Tetrarchy fell out of circulation in 306 when weight standards were reduced.

Byzantine Follis

In the Byzantine period, the follis was the largest denomination of copper coin, initially worth 40 nummi.

Also see:
Anonymous Folles
Anonymous Follis
Anonymous| Class |A |Folles