Following the same thread of suggestion and turning from the Eastern to the Western world, we pass at a leap from the Eastern gold stater of 192 wheat-grains to the gold solidus of Constantine, of exactly half that number.
Up to the time of Constantine there had been confusion in the currency of the Roman Empire. It had been mainly a silver currency. Few gold coins were in general circulation, and these were of various standards. But at last the gold solidus of Constantine placed the world in possession of a fixed gold standard acknowledged all over Europe and remaining unchanged till the fall of the Eastern Empire.
The importance of this fact is obvious. For our knowledge of most of the wergelds of the tribes conquered by the Merovingian Franks and later on by Charlemagne is dependent upon it, inasmuch as the laws in which the customs of these tribes were in some sense codified, almost always describe the wergelds in gold solidi.
The gold solidus of Constantine was fixed by him at 1/72 of the Roman pound or ⅙ of the Roman ounce.
The Roman pound (originally used for copper) was built up from the scripulum according to the duodecimal system of the As, thus:
| Scripulum | 24 | wheat-grains | = | 1·135 | grammes |
| Uncia (of 24) | 576 | ” | = | 27·25 | ” |
| Libra (of 288) | 6912 | ” | = | 327· | ” |
Gold tremisses of 32 wheat-grains.
The solidus of Constantine therefore contained 96 wheat-grains of gold, exactly the same number as the Eastern drachma, and half that of the stater or didrachma. At the same time smaller coins—thirds of the solidus, called trientes or tremisses—were issued in great numbers, and these tremisses contained 32 wheat-grains of gold, exactly the same number as the Greek diobol.
The normal wergeld of 200 gold solidi = gold mina.
So that, in wheat-grains, the very prevalent statement of the wergeld of the full freeman in the laws of various tribes as 200 gold solidi was in fact the same thing as a statement that the wergeld was a heavy gold mina, for 200 solidi of 96 wheat-grains contained exactly the same number of wheat-grains as did the heavy mina of ancient Eastern usage—viz. 19,200. In other words, so persistent seems to have been the traditional connection of the wergeld with the gold mina that Roman monetary usage was overruled, and instead of reckoning in Roman drachmas, ounces, and pounds, the wergelds were reckoned once more, or perhaps we should say continued to be reckoned, in what was really the heavy gold mina of 200 solidi.