The Tự Đức Bảo Sao was a series of large denomination Vietnamese cash coins produced under the reign of Emperor Tự Đức from 1861 to complement the contemporary Tự Đức Thông Bảo copper and zinc cash coins with larger nominal values. These coins were very badly received by the general population as their intrinsic value was relatively low compared to their nominal value and for this reason the Vietnamese government reduced the value of a single Tiền to 50 văn and allowed these coins to be used for the payment of taxes. The Tự Đức Bảo Sao is the first Vietnamese cash coin series that uses the denomination văn replacing the earlier weight based denomination of phân.
History
The Tự Đức Bảo Sao or Đồng Sao were introduced by the Ministry of Revenue in the year Tự Đức 14 for large transactions and taxes on behalf of stores of the government of Đại Nam, the introduction of the Tự Đức Bảo Sao marked the redefinition of the tiền or mạch denominations and the quàn where the quàn was made equal to 10 mạch and the mạch was made the equivalent of 60 zinc cash coins, under these exchange rates 1 quàn was worth a string of 600 zinc cash coins. The Đồng Sao series of cash coins was introduced as zinc cash coins were heavy in quantity to carry around for the payment of larger sums of money, to this end the government introduced a system of monetary units determined by their nominal value in zinc cash coins as opposed to their intrinsic market value, it is possible that this might have been inspired by contemporary Chinese coinage of the Xianfeng era in the Qing dynasty where large denomination coins from 4 up to 1000 văn circulated alongside each other with little to no difference in intrinsic value in a fiduciary system, this system was also used by the Vietnamese. When the Tự Đức Bảo Sao was first proposed the Mandarins of the imperial court of Đại Nam suggested to simply increase the weight of the brass Tự Đức Thông Bảo to make them worth more relative to the zinc Tự Đức Thông Bảo cash coins as 1 brass cash coin with a weight of 9 phần was worth four zinc cash coins. The value of the Đồng Sao cash coins was indicated on the reverses of the coins expressed in their worth in zinc cash coins preceded by the character , despite the fact that Sao means "paper money", though imperfectly the denominations of these coins attempted to take the respective value of brass and zinc cash coins into account which means that they can't be fully qualified as a fiat currency. The Ministry of Revenue of Đại Nam originally set the exchange rate between the brass Tự Đức Bảo Sao and zinc cash coins heavily in favour of the larger denominations which wasn't accepted by the market which resulted in the imperial court attempting to adjust the exchange rate more to the contemporary exchange values of brass and zinc cash coins that were in circulation. In January 1868 by decree the exchange rate between brass 9 phần cash and zinc cash coins was fixed 1:4 replacing the early ratio of 1:2.67 that had been in place since 1858. The Tự Đức Bảo Sao was generally well received by the population of Đại Nam despite the fact that their circulation was reduced due to their high purchasing power relative to their intrinsic value until their weight was decreased, which was done by the government to conform to the new official exchange between brass and zinc cash coins. From September 1870 the Tự Đức Bảo Sao series of cash coins has had their weight decreased, but kept the same nominal values and denominations. 80% of the Tự Đức Bảo Sao cash coins produced in the 1870 series were of the 60 văn denomination. The ratio in the alloy between copper and zinc of this series was highly irregular with the coins of 10 văn being 25% copper and 75% zinc while the coins of 60 văn were only 11.1% copper and 88.9% zinc. A decree enacted in 1870 halved the market value of zinc cash coins which maximised the profitability the government was making on the production of the Tự Đức Bảo Sao as they were low in weight relative to their nominal value. These new policies caused the Tự Đức Bảo Sao to fail however as the population were unhappy with these coins which were already little used, as these newer coins of decreased weight were rejected by the people they had to be re-melted as they were only used when people were forced to by the politicians. These coins were abandoned almost immediately after their manufacture and were rarely held by private individuals, they were however held in large quantities by metal founders and antique merchants especially in places like Hanoi where there were a lot of Europeans. The other series of Tự Đức Bảo Sao cash coins is not denominated in văn but in accounting units like mạch and quán, unlike the previous coins denominated in văn these coins could be considered to be a fiat currency. This series of the Tự Đức Bảo Sao is not mentioned in the contemporary Vietnamese annals. The intrinsic value of these coins is often only ten times as high as the lower denomination cash coins while their nominal value is a hundred times higher, it is possible that these coins were not introduced as their nominal value would be too different from the current system to be accepted by the population.
