Sweden , at the time a rising military power , soon intervened Hindering in 1630 under its king Gustavus Adolphus , transforming Change what had been simply the Emperor 's attempt to curb Hindering the Protestant states into a full-scale war in Europe .

Strategically , the loss Earnings_and_losses of Gustavus Adolphus meant Causation the French became Becoming the dominant power on the `` Protestant '' , or in their case , anti-Habsburg , side , eventually leading to Causation the founding Creating of the League of Heilbronn and the open Openness entry Process_start of France into the war Military_operation .