The Thirty Years' War was fought from 1618 until 1648. Though it was primarily centered in Germany, several other countries became involved in the conflict, including France, Spain, and Sweden. In fact, almost all of the powerful countries in Europe were involved in the war. It began as a fight about religion — the Protestants and Catholics were the two groups that disagreed. As the war continued, the Habsburg dynasty (a Catholic family) and other organizations used the war to try and get more power. One of the examples of this is that Catholic France fought for the Protestants. This made the France-Habsburg even worse.