Medal, awarded for contributions to Dutch industry to porcelain factory Dommer & Co. Silver, 1808. In 1806 France introduced an embargo on trade with Great Britain in an attempt to strangle the British economy. However, this measure, known as the Continental System, also had adverse effects for the continent. To support Holland's hard-pressed industries, Louis Napoleon introduced the first official national exhibitions, with prizes for the best achievers. These were the forerunners of the subsequent annual trade fairs.