Gold Standard (19th - 20th centuries)

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.