The war began as a dispute over a declaration by Duke Ferdinand and turned into a large-scale war between the religions Catholic versus Protestant, Calvinist and Lutheran. Although the war was started for religious reasons, the war ultimately ended up becoming a political tool used to limit Habsburg power in Spain. France, a Catholic power, and other anti-Catholic entities threw their support behind Gustavus Adolphus, who was a deeply religious Protestant fighting the largely Catholic Spain. This led to a division of the Holy Roman Empire and left Germany divided as Sweden, France and the Catholic Church carved out their territories through political means to augment their own party.