Byzantine coinage

Most provincial mints except for Syracuse were closed or lost to Arab Muslim invasions in the Mediterranean Region by the mid-7th century onwards.

Many mints, both imperial and, as the Byzantine Empire fragmented, belonging to autonomous local rulers, were operated in the 12th to 14th centuries.

Early Byzantine coins continue the late Greco-Roman conventions: on the obverse the head of the Roman Emperor, now full face rather than in profile;[note 1] on the reverse, usually a Christian symbol such as the cross or an angel (the two tending to merge into one another).

The gold coins of Justinian II departed from these stable conventions by putting a bust of Christ on the obverse,[note 2] and a half or full-length portrait of the Emperor on the reverse.

These innovations incidentally had the effect of leading the Umayyad caliph ʿAbd al-Malik, who had previously copied Byzantine styles but replacing Christian symbols with Islamic equivalents, finally to develop a distinctive Islamic style, with only lettering on both sides.

In the 10th century, so-called "anonymous folles" were struck instead of the earlier coins depicting the emperor.

Byzantine coins followed, and took to the furthest extreme, the tendency of precious metal coinage to get thinner and wider as time goes on.

It was succeeded by the initially ceremonial miliaresion established by Leo III the Isaurian in ca.

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.

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.

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.

Under Alexius I Comnenus (1081–1118) the debased solidus (tetarteron and histamenon) was discontinued and a gold coinage of higher fineness (generally .900-.950) was established, commonly called the hyperpyron at 4.45 grs.

At Jerusalem in the sixth century a building worker received 1⁄20 solidus per day, that is 21 folles.