The start of what is viewed as Byzantine currency by numismatics began with the
monetary reform of
Anastasius I in 498, who reformed the late Roman Empire coinage system which consisted of the gold
solidus and the bronze
nummi. The
nummus was an extremely small bronze coin, at about 8–10 mm, weight of 0.56 g making it at 576 to the
Roman pound which was inconvenient because a large number of them were required even for small transactions. half-follis, 20
nummi. Note the
K on the reverse. New bronze coins, multiples of the
nummus were introduced, such as the 40
nummi (also known as the
follis), 20
nummi (also known as a half
-follis), 10
nummi (also known as the
decanummium, and 5
nummi coins (also known as the
pentanummium); other denominations were occasionally produced. The obverse (front) of these coins featured a highly stylized portrait of the emperor while the reverse (back) featured the value of the denomination represented according to the
Greek numbering system (M=40, Λ=30, K=20, I=10, E=5). Silver coins were rarely produced.
miliaresion. The only regularly issued silver coin was the
hexagram first issued by
Heraclius in 615 which lasted until the end of the 7th century, minted in varying fineness with a weight generally between 7.5 and 8.5 grams. It was succeeded by the initially ceremonial
miliaresion established by
Leo III the Isaurian in ca. 720, which became standard issue from ca. 830 on and until the late 11th century, when it was discontinued after being severely debased. Small transactions were conducted with bronze coinage throughout this period. The gold
solidus or
nomisma remained a standard of international commerce until the 11th century, when it began to be debased under successive emperors beginning in the 1030s under the emperor
Romanos III Argyros (1028–1034). Until that time, the fineness of the gold remained consistent at about 0.955–0.980. . The Byzantine monetary system changed during the 7th century when the 40
nummi (also known as the
follis), now significantly smaller, became the only bronze coin to be regularly issued. Although
Constantine IV attempted a restoration of the
follis size of
Justinian I, the
follis, his reform was promptly abandoned after his death and folles continued to decrease in size. In the early 9th century, a three-fourths-weight solidus was issued in parallel with a full-weight solidus, both preserving the standard of fineness, under a failed plan to force the market to accept the underweight coins at the value of the full weight coins. The 11⁄12 weight coin was called a
tetarteron (a
Greek comparative adjective, literally "fourth-er"), and the full weight solidus was called the
histamenon. The
tetarteron was unpopular and was only sporadically reissued during the 10th century. The full weight solidus was struck at 72 to the Roman pound, roughly 4.48 grams in weight. There were also solidi of weight reduced by one
siliqua issued for trade with the Near East. These reduced solidi, with a star both on obverse and reverse, weighed about 4.25 g. The Byzantine solidus was valued in Western Europe, where it became known as the
bezant, a corruption of
Byzantium. The term
bezant then became the name for the heraldic symbol of a
roundel, tincture
or – i.e. a gold disc. ==Alexius I reforms==