main coinage had been the high-quality solidus or nomisma, which had remained standard in weight and gold content through the centuries. The Emperor Nikephoros II Phokas (r. 963-969), however, introduced a new coin which was a 2 carats (i.e. about ¹/₁₂, despite its name) lighter than the original nomisma, which now became known as the histamenon.

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