weights were often in the shape of a Byzantine empress. The ordinary units used for measurement of
weight or
mass were mostly
Roman, based on the late
Roman pound. This has been reconstructed on the basis of known legislation of
Constantine the Great in AD 309 establishing 72 gold
solidi (,
nómisma) to the pound. As the early solidi weighed 4.55
g, the pound was therefore 0.3276 kg at the time. The solidus was repeatedly
debased, however, implying average pounds of 0.324 kg (4th–6th century), 0.322 kg (6th–7th century), 0.320 kg (7th–9th century), 0.319 kg (9th–13th century), and even less thereafter. Model weights were made in
lead,
bronze, and
glass and (less often) from
gold and
silver. They came in various styles. Presently, archaeologists believe the bronze spheres sliced flat at top and bottom and marked with an
omicron/
upsilon date from the early 3rd to late 5th centuries, gradually being replaced by cubes marked with a
gamma/
omicron (
𐆄) over the course of the 4th century. In the second half of the 6th century, these were replaced by discs until at least the early 9th century and possibly the 12th. The glass weights had numerous advantages in manufacture and use but seem to have disappeared following the loss of the empire's
Syrian and
Egyptian provinces in the 7th century. Analysis of the thousands of surviving model weights strongly suggest multiple local weight standards in the Byzantine Empire before the
Arab conquests. Under
Justinian, the weights of currency were administered by the '
and commodity weights by the praetorian prefect and eparch of the city. By the 9th century, the eparch nominally controlled all official weights in Constantinople, although archaeology has shown others issued their own weights, including proconsuls, ', and ''
in the west and anthypatoi'',
counts, and
ephors in the
east. ==See also==