In the classical world, each country has a national currency. It's not only tool to control the national economy, but also the exression of its sovereignty, often symbol of the power in place and that of the time.

In the modern world, countries are gradually abandoning this privilege to adopt a single currency, Europe is in this way: the Euro has replaced the French Franc, German Deutch Mark, Spanish Peseta, Italian Lira, etc. ...

One day the Chinese will abandon the Yuan, the U.S. Dollar, European Euro, Japanese Yen, the Algerians Dinar to adopt the Mondo (世元 Shì Yuán, 世界元)? We'll probably not see it in our lifetime.

But we have already taken a big step toward that future, the currencies are convertible: in effect whatsoever between the Yuan and Dollar or the Euro and Yen, Dinar and Ruble, according to a conversion rate more or less variable, depending on the power of the countries concerned. This means that the money in the world have the same color and same flavor ...

The Chinese currency has undergone a significant evolution to result in current Yuan. Since millennia, the Emperors have wrought all their money in Precious metal printing their names in the dynasty. In Last Dynasty Qing 清朝, for example, money is Bronze Round with a square hole in the middle, also called TóngQián 铜钱, Copper money. We see the importance of money, everything was symolic: circle is a representation of Heaven in the imagination of the Chinese, and Square Earth. As Heaven surrounds the Earth, so the round contains the square, the universe is so complete and perfect. One assigns the magical powers to the metal currency, in Feng Shui, it's able to ward off evil minds. Here is a Summary table of Emperor - Imperial Chinese Currency: