After the demise of Napoleon's Empire, the Congress of Vienna of 1814–15 redrew the European map, intending to create a balance of power. One of the borders to be delineated was the one between the newly created United Kingdom of the Netherlands and the Kingdom of Prussia. Both parties could agree on the larger part of the territory, as borders mostly followed older lines, but the district of Moresnet proved problematic, mainly because of a valuable zinc spar mine named Altenberg (German) or Vieille Montagne (French) located there. The governments of both the Netherlands and Prussia desired to appropriate this resource, which was needed for the production of zinc and brass – at that time, Bristol in England was the only other place where zinc ore was processed.