Roman Republic AR Sestertius(12.75 mm, 1.14 g). Anonymous, first anonymous denarius coinage series. Circa 211 B.C. Rome mint. Helmeted head of Roma right; behind, IIS. Border of dots / Dioscuri galloping right; in linear frame, ROMA. Line border. Crawford 44/7; Sydenham 142; RSC 4; Russo RBW 176-177.
Most collectors of Roman coins think of the sestertius as a large bronze coin, however when the denarius coinage was introduced circa 211 B.C. the sestertius was a tiny silver coin worth one-quarter of a denarius. This coin bears the same devices as a denarius, save for the mark of value of "IIS" for "two and a half" asses. The silver sestertius was minted a handful of times throughout the Republican period and then saw a short revival near the end of the Republic before finally officially becoming a bronze coin as part of the coinage reform of Augustus.