Denarius Debasement of the coin's silver content continued after Nero. Later Roman emperors reduced its content to 3 grams around the late 3rd century. The value at its introduction was 10 asses, giving the denarius its name, which translates as "containing ten". In about 141 BC, it was re-tariffed at 16 asses, to reflect the decrease in weight of the as. The denarius continued to be the main coin of the Roman Empire until it was replaced by the antoninianus in the middle of the 3rd century. The coin was last issued, in bronze, under Aurelian between AD 270 and 275,
Silver coin was governed by caliphs, thus named 'the Caliphate'. As the caliphate expanded into Byzantine territories to the Northwest and conquered the Sassanian (Persian) Empire to the Northeast, the question of a caliphal coinage became imminent. The caliphate adapted the Sassanian drachm as their silver coin. Initially, Arabic inscriptions were added to the Sassanian coin type. Later, the type was completely revised, so as to include inscriptions and ornaments only. (Depictions of human beings is prohibited according to Sunni Islam). These coins are known in Arabic as "dirhem"s. The dirhems of the caliphate gained wide acceptance. They are consequently found along