to how the supply and demand of copper was regulated through government channels, supply and demand of silver was determined solely by the market. The domestic silver production in China was generally low and the silver in China came mostly from Edo Japan and later from the Americas, mainly through international trade with foreign merchants. This situation of silver in Qing China is similar to that of medieval England. The Kingdom of England did not produce significant amounts of silver by itself and therefore its coinage was closely associated with its overseas and international trade. The monarchs, both in imperial China and in the Kingdom of England, did not own the native silver supply. But unlike the English Crown, which had set up royal mints in England to strike the silver bullion into coins with a nominal (or face) value, the Chinese Emperor allowed only silver bullion itself to circulate in various forms throughout his empire. The government of the Qing dynasty provided only the standard unit (known as the Kuping tael) that a silver ingot should be melted into, which itself evolved into one of the many different "taels" that was used for silver bullion to be traded. Because the purchasing power of silver bullion was so much higher than that of copper-alloy cash coins, silver was used primarily for larger transactions and long-distance trade as well as international trade, while copper-alloy cash coinage was therefore not taken as subsidiary money: it was the currency for daily and smaller transactions and copper was the only currency in rural China during the Qing dynasty period. Silver also enjoyed a special status as it was also the major form of currency that was used for the payment taxes and government expenditures. Because of this, the government of the Qing dynasty had attempted to establish a fixed rate for the exchange of copper-alloy cash coins and silver bullion. During the majority of the Qing dynasty period, the official ratio between silver (in taels) and copper-alloy cash coins (in wén) was maintained at 1:1,000. The ratio was later revised to 1:2,000 during the 1840s, due to the rising price of silver. This theoretical official exchange rate was in practice not enforced by any government institution as because the imperial government did not coin any silver, it had no control over how silver circulated on the market. As the silver flow was primarily based