Roman Half Follis

The "Half-Follis" (plural: "half-folles") was a fraction of the billon follis.  Although the follis was introduced by Diocletian in 294, the half-follis wasn't struck (aside from a single example known from Alexandria in 295) until the Tetrarchal abdication issues of 305-7.  Fractional aes between 294 and 307 were supplied by both the "post-reform radiate" and "Ae denarius".  Those fractions were 1/2 and 1/5 of a follis, respectively. However the Ae denarius was never very common and the radiates ceased to be struck about 299 in the west and by 307 in the east. The gap was filled by the striking of a laureate coin of about 3.0 grams for the abdication issues which today is called a half-follis even though the 3-gram coins were more like 1/3 of a follis by weight.

Since the follis was probably tariffed at 20 sestertii or 5 argenteii (see "Argenteus"), the half-follis was naturally worth 10 sestertii or 2.5 argentei. The busts were always laureate, including the veiled "divus" busts. The diameter of the earliest half-follis was 21 millimeters, but by 318 they had shrunk to approximately 16 millimeters.

The so-called "half-follis" was rarely struck after the abdication issue until a final issue about 317-318 of the "divus" series Constantine I struck in memory of his father-in-law Maximian, his father Constantius I, and his distant relative Claudius II.  By that time the follis had degraded to about 3.5 grams, so the halves were in the range of 1.3-1.6 grams, again somewhat light. The advent of the "VICTORIAE LAETAE PRINC PERP" type (which was probably re-tariffed at 12.5 "denarii communes") is generally accepted as being the first of the "Ae3" denomination which replaced the follis and its fractions.  The "half-follis" thus lasted only a little over ten years, and was only occasionally struck during that short period.