What changed this was the Thirty Years War in Europe in the 17th century.

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And yet during the period of the Thirty Years War (1618-1648) Elizabeth was one of the foremost power brokers for the Protestant cause in Europe.

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The court of Louis XIV was impressed as much by the neckerchiefs of Croat mercenaries employed to fight the Thirty Years War as by their fighting spirit.

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In 1632, Sweden's King Gustavus II was killed during the Battle of Lutzen in the Thirty Years' War.

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In 1675, Henri de Turenne, French military leader in the Thirty Years' War, was killed during the Battle of Sasbach during the Dutch War.

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For thirty years, after the second world war Labour Governments thought their job was to manage an inevitable economic decline.

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After Gertrude's death, the dynasty she had put in place continued for thirty-two more years, while Europe plunged into war again after only thirteen, dragging the rest of the world with it.

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Yet a mere thirty years after the end of the Franco-Prussian War, when the smallpox epidemic swept through the United States, a whole host of intelligent people refused to be vaccinated, convinced that the vaccine did more harm than good.

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