Over the past 2,000 years, the leading international currency has changed many times, from the Roman denarius via the Byzantine solidus to the Dutch guilder and then to sterling.
Indeed, the word "soldier" derives from solidus, the Roman gold coin; in other words, a soldier was one who fought for money.In recent decades, mercenaries have been pushed to the wilder edges of global conflict: the "dogs of war" who fight nasty little campaigns in Africa.
The establishment by Constantine of a new gold coin, the solidus, which was to survive for centuries as the basic unit of Byzantine currency, could hardly have been achieved without the work of his predecessors in restoring political and military stability after the anarchy of the 3rd century.
Gold, however, continued in good supply; and though Constantine's solidus showed a reduced weight standard, there was no shortage of gold throughout the rest of the 4th century.
The A-B-C line represents the liquidus points (i.e., the temperatures at which molten iron begins to solidify), and the H-J-E-C line represents the solidus points (at which solidification is completed).
In order to reorganize finances and currency, Constantine minted two new coins: the silver miliarensis and, most importantly, the gold solidus, whose stability was to make it the Byzantine Empire's basic currency.
For example, when the liquid has reached A, at 1,400 °C, about 65 percent plagioclase with about 73 percent An (point O on the solidus) has crystallized from the liquid, which is now at about 36 percent An and 64 percent Ab.
From the time of Basil II (976 1025) the fabric of the gold nomismata (successor of the solidus) and also of the silver began to change, from using a narrower, thicker blank (flan) to one wider and thinner, which was also given a curious cup shape, hence the name nummi scyphati (cup money); gold scyphati declined in purity until, under Nicephorus III (1078 81), they were very base.
Emphasis on gold continued, with silver and some bronze; gold chiefly served for the triens, or third (1/3 of the Constantinian solidus).
The Ostrogothic coinage that followed, from Theodoric (493 526) onward, consisted of gold, mainly imitating current Byzantine issues and with the imperial portrait (Theodoric's fine portrait on a unique triple solidus is wholly exceptional).
