Hyperpyron

The hyperpyron (Greek: νόμισμα ὑπέρπυρον nómisma hypérpyron) was a Byzantine coin in use during the late Middle Ages, replacing the solidus as the Byzantine Empire's standard gold coinage in the 11th century. It was introduced by emperor Alexios I Komnenos.

History

The traditional gold currency of the Byzantine Empire had been the

carats for seven centuries and was consequently highly prized. From the 1030s, however, the coin was increasingly debased, until in the 1080s, following the military disasters and civil wars of the previous decade, its gold content was reduced to almost zero.^[1] Consequently, in 1092, Emperor Alexios I Komnenos (r. 1081–1118) undertook a drastic overhaul of the Byzantine coinage system and introduced a new gold coin, the hyperpyron (meaning "super-refined"). This was of the same standard weight (4.45 grams) as the solidus, but only 20.5 carat purity (0.854 fineness) instead of the standard 24 carat, resulting in a reduced gold content of only 4.1 grams instead of 4.8 grams. The lower purity was due to melting down and inclusion of earlier debased coins.^[2]

The hyperpyron remained the standard gold coin until gold coins ceased to be minted by the Byzantines in the mid-14th century. It too, however, was subject to gradual debasement: under the

keratia.^[4]

The name was adopted in various forms by Western Europeans (

Latin: perperum, Italian: perpero) and the Slavic countries of the Balkans (perper, iperpero, etc.) designating various coins, usually silver, as well as moneys of account.^[5] More often in the West the hyperpyron was called the bezant

, especially among Italian merchants.

In the early

assaria.^[7]