Russia's desire for an outlet on the Baltic Sea, and for control of the Baltic coast, was frustrated by five hundred years of persistent German eastward expansion. This "Drang nach Osten", or drive to the east, was a consistent theme of German conquest, colonis- ation and trade; and of Roman Catholic proselytism. By 1500 most r of the towns shown here had large German merchant communities. From 1500 to 1772 the Baltic territories were the scene of frequent conflicts between Lithuania, Poland, Sweden and Prussia.