Ever since Emperor Constantine I () introduced it in 309, the Byzantine Empire's main coinage had been the high-quality solidus or nomisma, which had remained standard in weight (4.55 grams) and gold content (24 carats) through the centuries. Emperor Nikephoros II Phokas (), however, introduced a new coin, the [nomisma] tetarteron ("quarter [coin]") which was 2 carats (i.e.
Since Emperor Constantine I () implemented it in 309, the Byzantine Empire's primary currency had been the solidus or nomisma, maintaining consistent weight (4.55 grams) and gold content (24 carats). However, Emperor Nikephoros II Phokas (), introduced a new coin, the [nomisma] tetarteron ("quarter [coin]") which was 2 carats.