This empire stamped its coins with a symbol representing both the number 72 and refined gold, according to Philip Grierson’s catalog of its coinage in the Dumbarton Oaks and Whittemore Collections. The coat of arms of the Duchy of Cornwall feature multiple coins whose name refers to their origin in this empire. One ruler of this empire introduced a coin called the hyperpyron to replace the (15[1])(*) nomisma. A debased coin in this empire known as (-5[1])tetarteron was referenced in a commercial guide called the Book of the Prefect. This was the latter of two empires to produce a gold coin called the solidus, (10[1])which was discontinued by this emperor’s Komnenos dynasty. (10[1])For 10 points, name this empire whose currency often featured (10[1])its emperors like Justinian. ■END■