 France supported the Dutch war with Spain, as well as funding Danish, then Swedish intervention in the Empire.In 1630, Gustavus Adolphus of Sweden invaded Pomerania; partly to support his Protestant co-religionists, he also sought control of the Baltic trade, which provided much of Sweden's income.Economic issues meant Swedish intervention continued after Gustavus was killed in 1632, but led to conflict with Saxony, Brandenburg-Prussia and Denmark-Norway.