Byzantine coinage began effectively with the reign (491–518) of Anastasius I. Thenceforth, it consisted, in addition to gold, of silver and bronze. Silver, always rather rare, consisted of the small siliqua (1/24 of a solidus) or keration, followed by the larger miliaresion and the still larger hexagram. Bronze was in most periods very commonly struck. Its appearance and tariffing were reformed by Anastasius, who issued large pieces marked M, K, I, and E (equal to 40, 20, 10, and five nummi); other multiples were found either later or locally, as IB (equal to 12 nummi) at Alexandria. Such marks of value continued until Basil I (867–886). Constantinople itself was the main mint in all three metals, which were coined also at Carthage and Ravenna. Thessalonica, Nicomedia, Cyzicus, Antioch, and Alexandria struck bronze only; at one time or another Rome struck gold and bronze, while Syracuse and Catana also contributed. The technique of gold and silver minting was generally high; that of bronze was coarse, and overstriking was common.

The obverses of the silver coins, beginning with profile busts, thereafter included seated figures, facing busts, and purely epigraphic designs. The introduction of the larger hexagram by Heraclius in 615 allowed fuller scope for later designers, whose reverses often consisted of a cross on steps or a bust of Christ surrounded by inscriptions; from the 10th century the cross bore a central portrait medallion of the emperor himself.

In bronze coinage there was at first less flexibility. The earliest types were, obverse, a profile bust and, reverse, a cross and mark of value. Under Justinian I the facing bust prevailed, and in his 12th year he introduced the dating of his bronze coins on the reverse, in the form Anno XII; the inclusion of a regnal date was thereafter normal on bronze until Constans II (641–668). From the time of Justin II (565–578) the obverses showed two or more standing imperial figures combined (until Basil I) with the mark of value. From the 10th century the reverses were taken up wholly by three or four lines of inscription; and the anonymous bronze coins of John Tzimisces combined such a reverse, reading Iesus Christus Basileu(s) Basile(on), with a new obverse showing the facing bust of Christ designated Emmanuel.

The orthography of Byzantine coin legends became remarkably complex as the Latin and Greek alphabets were increasingly mingled and individual letters took on new or specialized forms and words were severely abbreviated. At first the inscriptions were purely Latin, the emperor’s names and titles being in the conventional form D(ominus) N(oster)—P(ius) F(elix) Aug(ustus). Even before Anastasius, however, Perpetuus had been a variant for P.F., and, abbreviated in the form PP, it finally prevailed. In the 7th century, Greek letters were more commonly mixed with the Latin in such legends as that of Justinian II, when he styled himself Servus Christi; and in the later 8th, the general shift to Greek from Latin conceptions was plain in the emperor’s new title of Basileus. Comparatively long votive inscriptions, as “Lord, help thy servant,” and metrical inscriptions (a practice more common in Asia than in Europe) began in the 10th century.