The film charts the brutal military campaign:

It highlights the deep-seated ideological rift between King Charles I and Parliament over taxation, religion, and the limits of monarchical authority.

Writing the screenplay himself, Hughes faced a daunting task. The English Civil War spanned years and involved complex political machinations that could easily become dry or confusing. To solve this, he focused the narrative intensely on the relationship between two men: Oliver Cromwell and King Charles I. The film strips away many of the sub-plots of the era to focus on this central ideological collision.

The primary reason to search for Cromwell the movie remains the electric chemistry between its two male leads.

The film’s narrative engine is the collision of two worldviews. On one side is Cromwell, representing the rights of Parliament and, ostensibly, the common man. On the other is Charles, representing the ancient order and the belief that the King is God’s lieutenant on Earth.