Set against the tumultuous backdrop of the English Civil War (1642-1651), this epic historical fiction follows two noble families torn apart by political conviction and united by unexpected love. The Cavendish family, led by William, Earl of Newcastle, represents the Royalist cause—aristocrats who believe in the divine right of kings and traditional order. Opposing them are the Hampdens, headed by the principled John Hampden, Parliamentary champions who fight for constitutional government and the rights of Englishmen.

The story begins in 1641 as tensions between King Charles I and Parliament reach breaking point. In a London tavern, Charles Cavendish, younger brother to the Earl of Newcastle, encounters William Hampden in a heated political debate. Their philosophical sparring is interrupted when William's sister Ruth needs assistance with her lame horse. Charles gallantly escorts her home, where he meets John Hampden himself. Despite their political differences, mutual respect develops, and Charles finds himself captivated by Ruth's intelligence and beauty.

As civil war erupts in 1642, the families choose their sides. The Cavendishes rally to King Charles I's standard at Nottingham, while John Hampden takes command of a Parliamentary regiment. Charles and Ruth's forbidden romance blossoms through secret correspondence, their love transcending the growing chasm between their worlds. Their relationship symbolizes the personal cost of political division—two souls united by affection yet separated by loyalty to opposing causes.

The war's brutal reality unfolds through major battles. At Edgehill, the first great engagement, both sides suffer heavy casualties without decisive victory. Charles fights bravely for the King while wondering if William Hampden stands among the enemy ranks. The northern campaigns see William Cavendish commanding Royalist forces in Yorkshire, while his daughter Jane defends Welbeck Abbey against Parliamentary siege.