Charles I firmly believed in the divine right of kings, which held that the monarchy's authority was granted directly by God. This belief led him to resist attempts by Parliament to limit his power. He viewed his role as God's appointed ruler and rejected any interference in his decisions. This absolutist philosophy, however, set the stage for intense conflicts with Parliament, particularly regarding issues of taxation and governance.

Charles’s reign was marked by increasing tensions with Parliament. He dissolved Parliament multiple times when it opposed his policies, particularly over issues like taxation and the funding of wars. One of his most controversial decisions was the imposition of "Ship Money," a tax on coastal towns to fund the navy, which was seen as an overreach of his authority. These actions led to widespread protests and growing resentment toward his rule.

In 1642, the conflict between the monarchy and Parliament escalated into the English Civil War. Charles I's refusal to compromise with Parliament led to a violent and prolonged civil conflict. The Royalists (Cavaliers) fought against the Parliamentarians (Roundheads), with key battles such as Edgehill and Naseby shaping the course of the war. Ultimately, the Parliamentarians emerged victorious, and the monarchy’s power was severely weakened.