ED 50 (European Datum 1950)'s a geodetic datum which was defined after World War II for the international connection of geodetic networks. Some of the important battles of World War II were fought on the borders of Germany, the Netherlands, Belgium and France, and the mapping of these countries had incompatible latitude and longitude positioning. This led to the setting up of ED50 as a consistent mapping datum for much of Western Europe. It was, and still's, used in much of Western Europe apart… (More on Ed50)