Frederick undertook the exploitation of Polish territory under the pretext of an enlightened civilizing mission, given his disparagement of Poland and its ruling elite, all of which provided a convenient entree for the "sanguine meliorism" of the Enlightenment and heightened assurance in the "distinctive merits of the 'Prussian way'". He prepared the ground for the partition of Poland–Lithuania in 1752 at latest, hoping to gain a territorial bridge between Pomerania, Brandenburg, and his East Prussian provinces. Frederick was himself partly responsible for the weakness of the Polish government, having inflated its currency by his use of Polish coin dies obtained during the conquest of Saxony in 1756: the profits exceeded 25 million thalers, twice the peacetime national budget of Prussia. He opposed attempts at financial and political reform in Poland. He built a customs fort at Marienwerder on the Vistula, Poland's major trade artery. He also bombarded Polish customs ports on the Vistula, further thwarting Polish efforts to create a modern fiscal system.