Tetarteron

The ''tetarteron'' ( el, �όμισματεταρτηρόν, "quarter oin) was a Byzantine term applied to two different coins, one gold circulating from the 960s to 1092 in parallel to the ''histamenon'', and one copper used from 1092 to the second half of the 13th century.

Gold coin

Ever since Emperor Constantine I (r. 306–337), the Byzantine Empire's main coinage had been the high-quality ''solidus'' or ''nomisma'', which had remained standard in weight and gold content through the centuries. The Emperor Nikephoros II Phokas (r. 963–969), however, introduced a new coin which was a 2 carats (i.e. about ¹⁄₁₂, despite its name) lighter than the original ''nomisma'', which now became known as the ''histamenon''...

The exact reason for the introduction of the ''tetarteron'' is unclear. According to the historian Zonaras, this was done to increase state revenues: the taxes were to be paid as before in the ''histamenon'', while the state paid its own expenses in the less valuable ''tetarteron'', which was officially rated as equal to the full ''histamenon'', instead. Modern scholars have alternatively suggested that the ''tetarteron'' was an imitation of the Muslim gold dinar, for use in the eastern provinces recently reconquered from the Arabs, or perhaps an element of an abortive monetary reform that intended to replace the ''histamenon'' altogether. At any rate, the ''tetarteron'' was issued only in small quantities in the 10th century, and only from the mid-11th century on was it minted in quantity approaching the ''histamenon''.

Initially, the two coins were virtually indistinguishable, except in weight. During the later reign of Basil II (r. 976–1025), the ''tetarteron'' began to be minted in a thicker and smaller form, while the ''histamenon'' conversely became thinner and wider. Only during the sole rule of Constantine VIII (r. 1025–1028), however, did the two coins become iconographically distinct as well.. By the mid-11th century, the ''tetarteron'' measured 18 mm wide and its weight apparently standardized at 3.98 grams, i.e. three carats less than the ''histamenon'', which now measured 25 mm in diameter (as opposed to 20 mm for the original ''solidus'') and had acquired a slightly concave (scyphate) form. However, starting with Michael IV (r. 1034–1041), who was a former money lender, the gold content began to be increasingly lowered and the coins debased. After a period of relative stability in circa 1055–1070, the gold content declined dramatically in the period of crisis in the 1070s and 1080s. During the first eleven years of the reign of Alexios I Komnenos (r. 1081–1118), the last gold/electrum ''tetarterons'' were issued. Alexios reformed the whole Byzantine coinage in 1092 and eliminated the gold/electrum ''tetarteron'' and gold/electrum ''histamenon''. In its place he introduced a new gold coin called the ''hyperpyron''.

Copper coin

In 1092, Alexios I Komnenos (r. 1081–1118) reformed the imperial coinage, introducing the ''hyperpyron'' gold coin instead of the devalued ''histamena'' and ''tetartera''. Alexios also instituted a new copper coinage (although many of the first examples were struck of lead) to replace the old ''follis''. Apparently due to its similar dimensions and fabric to the gold ''tetarteron'', it was also named ''tetarteron'' or ''tarteron''. It has, however, also been suggested that its name derives from it being worth one quarter of the late, debased ''follis'' of the 1080s. The new coin, flat, weighing circa 4 grams and valued (at least initially) at 864 to the gold ''hyperpyron'', was struck in great quantities and in a large variety of designs, especially in the 12th century. A half-''tetarteron'' was also minted. Both coins remained relatively stable in weight, but begin to appear less frequently towards the turn of the 13th century.

In the 13th century, copper ''tetartera'' were issued by the rulers of the Empire of Thessalonica in the 1230s and 1240s, as well as by the Empire of Nicaea (1204–1261). In the restored Byzantine Empire, from 1261 on, they appear to have been replaced by a new type of copper coins named '' assaria'' after the ancient Roman coins..

References

Sources

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* Димов, Г. Провалите и фалшификациите във византийската монетна политика през X век. Появата на тетартерон и диотетартетон номизма. - В: Mediaevalia, 3, 2011, 237-245.

{{Byzantine coinage

Gold coins
Coins of the Byzantine Empire