The monetary system of Christian Spain dates from the Gothic invasions, and differs from that of Germany, Italy, and France in being derived in the first place from the Roman system without the intermediation of that of Charlemagne.
Under the Goths the monetary basis was the Roman libra, subdivided thus—
1 libra = 8 onzas = 4608 grs.
1 onza = 8 ochavas = 576 grs.
1 ochava = 6 tomines = 72 grs.
1 tomin = 3 quilates or siliqua = 12 grs.
The unit denomination was the sueldo de oro (gold sueldo) = 1⁄6 onza of the fineness of 23 3⁄4 quilates (=.989 fine), corresponding exactly to the Roman aureus of the times of Julian.
The unit denomination of the silver money was twofold—(1) the silver sueldo (= 1⁄6 onza like the gold), and (2) the denario ( 1⁄8 onza or ochava). The silver coins were at first of 12 dineros fine, but subsequently only 10.12 (=.875 fine).
Of these two units, the latter, the silver denario was far the more usual and frequent in use.
With one important change of name, and infinite change of incident and detail, it was this system which obtained till the great reform of the Spanish monetary system under Ferdinand and Isabella.
The change of name consists in the introduction of that of the maravedi, which was adopted from the conquered Moors, and applied to designate the sueldo d'oro from the time of the conquest of Toledo.
In a comprehensive way it may be said that the history of this word or name, maravedi, sums up the monetary history of Spain. From being the original gold coin of highest denomination, it came to be a silver coin, then a billon coin of the very lowest denomination, as it is to-day. The process of its degeneration is quite unexampled even in Europe. In addition, also, to the confusion of idea produced by this depreciation there is a further uncertainty, caused by the quite general use of the word or name, i.e. not as the name of a particular coin or money series, but perfectly generally for almost any and every coin—as synonymous, in fact, with the simple word money itself.