Theodosius I, with Arcadius and Honorius. AE Exagium Solidi

Theodosius I, with Arcadius and Honorius. AE Exagium Solidi Weight. Constantinople mint, 402-408. Obv. . DDD NNN GGG. Diademed and draped facing busts of Honorius, Theodosius, and Arcadius respectively. Rev. EXAGIVM SOLIDI. Moneta standing left, holding scales and cornucopiae; wreath between palm branches in exergue. RIC X p. 8; Bendall, Byzantine Weights 9; Sabatier 8; Cf. Göbl, Antike 228-9. AE. 3.99 g. 21.00 mm. RR. A choice example, of excellent style. Unaltered by piercing or plugging, very rare thus. Lovely even deep brown patina. About EF/About VF. Official solidus weights, based on a standard 'imperial pound', came into being with the law of Julian of AD 363, which established a zygostates - an official weigher of solidi in each city to restore confidence in the solidus, which had become subject to widespread clipping. Exagium derives from the Latin exigere 'to drive out' - in this case, the underweight solidi, thereby maintaining an acceptable weight standard necessary for the imperial gold coinage to circulate at full value. Many, if not most, such exagia display holes and/or plugs to bring the exagium to the correct weight. Unmodified exagia are thus a rarity. (Roma Numismatics 9, 2015, 854.