From 1356, together with Lübeck and Cologne, Hamburg had been one of the leading cities in the "Hanse," a loose association of many North German cities, whose purpose was to facilitate trade between Russia and Poland on the one hand and North Germany, Scandinavia, Flanders and England on the other. And Hamburg also belonged to the Wendish coinage union, whose members issued their currencies jointly, including the mark. As can be seen on this coin, Hamburg was a "free imperial city," which meant that it was subject only to the direct authority of the German emperor, in this case Leopold I of Hapsburg, king of Hungary and Bohemia and emperor of the Holy Roman Empire (i.e. medieval Germany, 1658-1705). Free imperial cities had legal privileges such as their own courts – they were free. That is made clear by the coat of arms of the city on the obverse of the coin and the double-headed eagle of the emperor on the reverse.