Hyperpyron
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").It too, however, was subject to gradual debasement: under the Empire of Nicaea (1204–1261), its gold content fell gradually to 18 carats, under Michael VIII Palaiologos (r. 1259–1282) to 15 and under his son and successor Andronikos II Palaiologos (r. 1282–1328) to 12 carats.[3] The last hyperpyra, and thus the last Byzantine gold coins, were struck by Emperor John VI Kantakouzenos (r. 1347–1352).[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.)
Manuel I KomnenosscyphateByzantinelate Middle AgessolidusByzantine EmpireAlexios I KomnenosnomismacaratsByzantine coinageEmpire of NicaeaMichael VIII PalaiologosAndronikos II PalaiologosJohn VI Kantakouzenosmoney of accountkeratiaItalianSlavicBalkanssilverbezantKomnenian periodelectrumtracheabilloncoppertetarterabasilikatournesiaassariaMedieval Bulgarian coinageMontenegrin perperRagusan perperaSerbian perperKazhdan, AlexanderThe Oxford Dictionary of ByzantiumCurrenciesSemissisTremissisHexagramFollisHalf-follisDecanummiumPentanummiumNummusHistamenonMiliaresionNomisma trachyasprontrachyStamenonBasilikonTournesionPolitikonStavratonHalf-stavratonDoukatopoulonFollaroByzantine economyByzantine mints