yellow brass (orichalcum), and the as semis and quadrans in common red copper. This distinction of metals, however, was sometimes ignored, as in the time of Nero, when we have sestertius (Pl. III. fig. 2), dupondius and as, all in brass, and of three different sizes. The as is usually nearly equal in size and Weight to the dupondius, but is distinguished by its metal and inferior fabric. All this brass and copper coinage bears the letters S.C., senatus consulto. Emperors not acknowledged by the senate are without such money; thus we have no specimens of Otho or Pescennius Niger.
Nero reduced the denarius to 196th of the pound, and alloyed its silver with from 5 to 10% of base metal. Henceforward the quality of the denarius gradually sank, until under Sept. Severus the proportion of alloy was from 50 to 60%. Caracalla also issued lead plated with silver and, among his aurei, copper plated with gold. He also introduced a new coin, Changes under later emperors. called after him the argenteus Antoninianus. It was struck at 160th to 164th of the pound, and seems to have been originally a double denarius struck on a lower standard. The characteristic of this coin is that the head of the emperor is radiate as Sol (Pl. III. fig. 4), that of the empress on a crescent as Luna. Towards the end of Caracalla’s reign the weight of the aureus had fallen to 150 ℔. Under Elagabalus the taxes were paid in gold alone; this was ruinous, for the treasury paid in debased silver at nominal value, which had to be used to purchase gold by the taxpayer at real value. Under Gordian III. the silver contained 67% of alloy; and eventually under Gallienus the “argenteus” frequently contained no silver whatever. Aurelian (A.D. 270–275) attempted a reform of the coinage by which the previous coin was reduced from its nominal to its intrinsic value. The coins were now of bronze with a wash of silver, and we now find them marked with their value as two denarii. These coins replace at once the base silver and the bronze, which now disappear. The moneying right of the senate had become illusory by the depreciation of silver, which had ceased to have any real value. Aurelian entirely suppressed this right; Tacitus and Florian restored it for a few years, after which the S.C. disappears from the coinage. The reform of Aurelian caused a serious outbreak at Rome, but was maintained by him and by Tacitus. Aurelian also suppressed all local mints but Alexandria. It was the work of Diocletian to restore the issue of relatively pure money in the three metals. He made no less than four unsuccessful attempts to regulate the weight of gold. Not later than 290 he restored a pure silver coinage with a piece of 196 ℔. His reformed bronze coins are the follis, marked XX, XX·I., K, KA, &c. (all meaning “2 denarii＝the unit”) and the half-denarius of centenionalis.
Constantine, probably in A.D. 312 (though some critics attribute the reform to Constantius Chlorus) desiring to rectify the gold coinage, which had long been quite irregular in weight, reduced the chief gold piece to 172 of the pound, and issued the solidus (Pl. III. fig. 5), a piece destined to play a great part in commercial history. It was never lowered in weight, though many centuries later it was debased, long after it had become the parent of the gold coinages of Westerns and Easterns alike throughout the civilized world. The letters OB, which are commonly found in the exergue of gold coins from the 4th century onwards mean Obryzum (refined gold), and the letters PS, found on silver coins Pustulatum (refined silver). Under Constantius II. (A.D. 360) and Julian the silver coin of 196 ℔ was suppressed, and the siliqua of 1144th of the pound (which had already been issued in small quantities before) took its place. From about 360 there was a system of 4 bronze coins (follis, denarius, centenionalis and 12 centenionalis). The last soon disappeared, and under Honorius (395) only the centenionalis remained. Honorius and his successors issued the silver decargyrus (＝10 denarii). The bronze coinage of this time was small and mean. It will be seen that a fuller system of bronze was originated by Anastasius, the Byzantine emperor.
Under Augustus the Roman monetary system became the official standard of the empire, and no local mint could exist without the imperial licence. Thus the Greek imperial money is strictly Roman money coined in the provinces, with the legends and types of the towns. Many cities were allowed to strike bronze, several silver. The kings of the Cimmerian Bosporus enjoyed the exceptional privilege of striking gold, which, however, became rapidly debased. The silver becomes limited about Nero’s time, but lasts under the Antonines, and is also found under Caracalla and Macrinus. It is chiefly supplied by the mints of Caesarea in Cappadocia, Antioch and subsidiary mints in Syria, and Alexandria in Egypt. None of these were strictly city-mints, but served the purposes of the provincial government. The bronze increased in mints and quantity in the 2nd century, but, through the debasement of the Roman silver, one city after another ceased to strike about the middle of the 3rd, The provincial mint of Alexandria, however, continued to strike until the end of the century. From the coins of the ordinary Greek and other cities under the empire must be distinguished the issues of the Roman colonies. In the west these practically ceased in Nero’s time; in the east they lasted as long as the other Greek coinage. Purely Roman gold and silver was coined in certain of the provinces, in Spain and Gaul, and at the cities of Antioch and Ephesus. When the base silver had driven the Greek imperial bronze out of circulation, Gallienus established local mints which struck pure Roman types. Diocletian increased the number of these mints, which lasted until the fall of the empire of the West, and in the East longer. These mints were (with others added later), Londinium (or Augusta), Camulodunum, Treviri, Lugdunum, Arelate (or Constantina), Ambianum, Tarraco, Carthago, Roma, Ostia, Ravenna, Aquileia, Mediolanum, Siscia, Serdica, Sirmium, Thessalonica, Constantinopolis, Heraclea, Nicomedia, Cyzicus, Antiochia (ultimately Theupolis) and Alexandria. A few were speedily abandoned.
As regards the internal organization of the mints under the empire, we know that, although the names of the triumviri monetales do not occur on the coins after 15 B.C., they continued to exist (with the title IIIviri aere argento auro flando feriundo, although their competence was restricted to the first metal) until probably the time of Aurelian, who withdrew the right of coinage from the senate. Officials of the imperial treasury superintended the gold and silver coinage; Trajan placed a procurator monetae Augusti of equestrian rank at the head of the whole system, subject to the emperor’s rationalis (the chief official of the treasury). The system of procurators was extended and regularized by Diocletian. In the Roman colonies (which were only allowed to issue bronze) the formula D.D. or EX D.D. (ex decurionum decreto) often occurs, corresponding to the S.C. of the Roman mint. At many colonies, especially in the west, the monetary duumviri sign the coins. At Rome the imperial mint itself was situated behind the Colosseum, near the Caelian hill, the senate retaining its mint on the Capitol probably until the time of Trajan. The three monetae (of the three metals) appear together on medallions for the first time under Hadrian, and probably indicate the organization of the mints for the three metals in one place. From the middle of the 3rd century mint-marks begin to occur on the coins, indicating the various mints, the officinae in each mint, &c. Sometimes these marks form “secret combinations”; thus the letters I, O and BI found on three different coins of Diocletian (struck at three different officinae), and the letters HP, KOY and ΛΙ on three corresponding coins of Maximian, combine into Greek words representing the genitives of the Latin titles Iovius and Herculius assumed by these two emperors.
The obverse type of the imperial coins is the portrait of an imperial personage, emperor, empress or Caesar. The type only varies in the treatment of the head or bust—if male, laureate, radiate or bare; if female, sometimes veiled, but usually bare. The reverse types of the pagan period are mythological of divinities, allegorical Types and inscriptions. of personifications, historical of the acts of the emperors. Thus the coins of Hadrian, besides bearing the figures of the chief divinities of Rome, commemorate by allegorical representations of countries or cities the emperor’s progresses, and by actual representations his architectural works. Types often occur purely personal to the emperor, such as the sphinx which Augustus used as his signet, or the Capricorn, his natal sign. The most remarkable feature of imperial types is the increase of personifications, such as Abundantia, Concordia, Liberalitas, Pudicitia—for the most part drearily conventional. The inscriptions are either simply descriptive, such as the emperor’s names and titles in the nominative on the obverse, or partly on the obverse and partly on the reverse, and the name of the subject on the reverse; or else they are dedicatory, the imperial names and titles being given on the obverse in the dative and the name of the type on the reverse. Sometimes the reverse bears a directly dedicatory inscription to the emperor. The inscriptions on the earlier imperial coins from Tiberius to Severus Alexander are generally chronological, usually giving the current or last consulship of the emperor and his tribunitian year. It must be noted that Christian symbols first made their appearance on coins in an unsystematic, almost accidental way. The earliest instance is at the mint of Tarraco in A.D. 314, when a cross occurs as a symbol on the reverse. In A.D. 320 the Christian monogram is found as a detail in the field at several mints. But the types still remain pagan; these symbols are not introduced by order,
