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760

Mannen Tsūhō: Imperial Coin No. 2

Issued with the gold Kaiki Shōhō and silver Taihei Genpō. It was declared equal to ten Wado Kaichin, a policy that did not secure durable acceptance and encouraged private casting.

萬年通寶Mannen Tsūhō

Representative Mannen Tsūhō from the Tokyo National Museum Kōchō Jūnisen group 裏Other face not present in the approved source
Representative source face; the other face is unavailable.National Institutes for Cultural Heritage, Japan / ColBase · CC BY 4.0
Sequence
2 / 12
Issue year
760
Era
天平宝字 4
Authority
Imperial court under Emperor Junnin

Historical context

Issued with the gold Kaiki Shōhō and silver Taihei Genpō. It was declared equal to ten Wado Kaichin, a policy that did not secure durable acceptance and encouraged private casting.

Inscription and reading

萬年通寶 · Mannen Tsūhō · Man'nen Tsūhō, Man'nen Tsuho, Mannen Tsuho

Reading confidence · high

Observed catalog specimens

Measurements, metal, and cast fabric

These values are comparative observations, not official tolerances or authentication cutoffs.

Weight
2.56–6.69 g
Diameter
24.56–27.45 mm
Metal
copper alloy
Hole
central square hole
Rims
cast inner and outer rims; variable finishing
Casting
cast copper-alloy cash coin

Composition evidence

Early sampled coins are principally copper, tin, and lead with measurable iron in some specimens; composition is specimen-dependent.

Cu-Sn-Pb dominant in sampled specimens; some iron observed.

Attribution boundary

A named court and era establish issue context. They do not establish the physical mint of an unidentified specimen.

high for identity, sequence, issue date, and authority; medium for generalized specifications

Evidence

Sources and scope

These links support the claims on this page. Source authority does not imply permission to republish source images.

Wado Kaichin and Ancient Coinage Exhibition Catalogue, Pages 1–5 Currency Museum, Bank of Japan

Mumon Ginsen, Fuhonsen, Wado Kaichin, Mannen Tsuho, Jingu Kaiho, documentary issue dates, circulation policy, and reading evidence.

Open source
Measurement Catalog for Ancient Coin Types from Mannen Tsuho through Kengen Taiho Currency Museum, Bank of Japan

Specimen-level outer diameter and weight observations for issues two through twelve; observations are not statutory standards.

Open source
Chemical Composition Study of the Twelve Ancient Coin Types Institute for Monetary and Economic Studies, Bank of Japan

Measured copper, tin, lead, iron, arsenic, and antimony patterns across sampled ancient coins, with specimen-level limitations.

Open source