Hyperpyron
Appearance
The hyperpyron (Greek: ὑπέρπυρον) was a Byzantine coin in use in the latter Middle Ages. It was established by Emperor Alexius I Comnenus (1081–1118) to replace the debased solidus. The hyperpyron was of higher fineness gold (generally .900-.950) and weighed 4.45 grs.
It was equal to five ducats or twenty solidi, though the value of similarly-named coins was different in Cyprus and other Mediterranean countries.