Reserve currency before the beginning of the worldwide credit crunch related recession and Eurozone crisis, which harmed the euro and slowed its adoption. Since 2009, the reserve currency use of the euro has continued to drop, down to 23.9 percent in 2013. The Dutch guilder was the "de facto" reserve currency in Europe in 17th and 18th centuries. The United Kingdom's pound sterling was the primary reserve currency of much of the world in the 19th century and first half of the 20th century. The emergence of the USA as an economic superpower, and the establishment of the U.S. Federal Reserve System
World currency Habsburg territories. Prior to and during most of the 19th century, international trade was denominated in terms of currencies that represented weights of gold. Most national currencies at the time were in essence merely different ways of measuring gold weights (much as the yard and the meter both measure length and are related by a constant conversion factor). Hence some assert that gold was the world's first global currency. The emerging collapse of the international gold standard around the time of World War I had significant implications for global trade. Before 1944, the world reference currency was the United Kingdom's