After the [[Thirty Years' War]], Sweden gained posession of upper [[Pomerania]], some of lower Pomerania, and the [[Oder river|Oder]], [[Elbe river|Elbe]], and [[Weser river|Weser]] rivers, allowing them to collect tarriffs on shipping traveling on these vital trade arteries. | After the [[Thirty Years' War]], Sweden gained posession of upper [[Pomerania]], some of lower Pomerania, and the [[Oder river|Oder]], [[Elbe river|Elbe]], and [[Weser river|Weser]] rivers, allowing them to collect tarriffs on shipping traveling on these vital trade arteries. |