Tertarteron - John I Tzimiskes Constantinopolis

The tetarteron was introduced by Nikephoros II Phokas around 963 AD as a lighter gold coin intended to circulate alongside the traditional nomisma — a monetary experiment that generated significant contemporary complaint. The historian Leo the Deacon records that Nikephoros was accused of debasing the currency, though the tetarteron was technically pure gold, simply reduced in weight. John I Tzimiskes, who seized power by having Nikephoros murdered in December 969, continued the denomination without modification, making his issues typologically inseparable from reign politics of extraordinary violence.