In analyzing the motivations of the countries and peoples involved in the Thirty Years War, it is clear that religious factors were very important in comparison with political considerations. .
One religious factor that played a large role in this war stemmed from the Peace of Augsburg, which declared that each state could prescribe the religion of its subjects. This principle led to a widespread scramble to name successors to incumbents and thus secure a territory as either Lutheran or Catholic. In 1608 the Elector Palatine, formed a Protestant union to defend their gains. This was shortly followed by the creation of a league of Catholic German states organized by Bavaria. All of these factors came into play in Bohemia in 1618. The fighting of the Thirty Years War began in Bohemia when residents felt that their newly crowned King, Ferdinand of Styria, was denying the primarily Protestant country its religious liberties. The Bohemians deposed their king and appointed the Calvinist Elector Palatine in an effort to secure Protestant assistance. This was short-lived however, since the Elector Palatine was ousted in 1620 by Ferdinand who granted much of the Bohemian nobles" lands to the church to be used for Catholic churches, orders, and monasteries. With this, Ferdinand began the re-Catholicization of Bohemia. As a result of this the Protestant union collapsed and the Protestant affairs were taken over by the king of Denmark. Although he was managing the Protestant affairs, his concerns were more political than religious.
The king of Denmark had in interest in taking part in this war due to his dynastic concerns. Most of the new monarchies of the time were striving to create a kingdom that would be passed down to their children and stand the test of time. An example of this can be seen in Louis XI of France, who rounded out the borders of France through a combination of inheritance, marriage, war, intrigue, and conquest.