Final answer:
During the Thirty Years' War, the Protestant cause was supported by Sweden and France.
Step-by-step explanation:
During the Thirty Years' War, the Protestant cause was supported by Sweden and France. Sweden, under the leadership of King Gustavus Adolphus, intervened in the war on the Protestant side and won several key battles. France, a Catholic country, saw an opportunity to weaken the Habsburgs, who were the leading Catholic power, and formed alliances with Protestant states to counter their influence.
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