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.
History of the euro support the euro in 2001. Later in 2000, Denmark held a referendum on whether to abandon their opt-out from the euro. The referendum resulted in a decision to retain the krone, and also set back plans for a referendum in the UK as a result. The procedure used to fix the irrevocable conversion rate of 340.750 between the Greek drachma and the euro was different, since the euro by then was already two years old. While the conversion rates for the initial eleven currencies were determined only hours before the euro was introduced as a virtual currency, the conversion rate