Reserve currency economy, the German Deutsche Mark gained the status of the second most important reserve currency after the US dollar. When the euro was introduced on 1 January 1999, replacing the Mark, French franc and ten other European currencies, it inherited the status of a major reserve currency from the Mark. Since then, its contribution to official reserves has risen continually as banks seek to diversify their reserves, and trade in the eurozone continues to expand. Former U.S. Federal Reserve Chairman Alan Greenspan said in September 2007 that the euro could replace the U.S. dollar as the world's primary reserve currency.
International status and usage of the euro those in the eurozone, do not participate in the European Central Bank or the Euro Group. Its international usage has also grown as a trading currency, acting as an economic or political alternative to using the United States dollar. Its increasing usage in this sense has led to its becoming the only significant challenger to the US dollar as the world's main reserve currency. Several European microstates outside the EU have adopted the euro as their currency. For EU sanctioning of this adoption, a monetary agreement must be concluded. Prior to the launch of the euro, agreements were reached with