Aspron Trachy - Manuel I second coinage

Manuel I's second coinage aspron trachy reflects the ongoing debasement that had been slowly degrading Byzantine electrum since the reign of Constantine IX in the 1040s. By Manuel's era, the electrum content had fallen so far from the original nomisma standard that contemporaries and modern metallurgists alike have struggled to characterize the alloy consistently — some specimens in this type register well below 20% gold. The monetary reforms his successors were forced to undertake were a direct consequence of this incremental erosion.