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.
Poland and the euro Poland and the euro Poland does not use the euro as its currency. However, under the terms of their Treaty of Accession with the European Union, all new Member States "shall participate in the Economic and Monetary Union from the date of accession as a Member State with a derogation", which means that Poland is obliged to eventually replace its currency, the złoty, with the euro. There is no target date for Polish euro adoption, and no fixed date for when the country will join ERM-II (the fifth euro convergence criterion). The country's former Deputy Prime Minister Janusz Piechociński has