Richard Neville, Earl of Warwick, emerges as a powerful nobleman initially championing the House of York in the Wars of the Roses. He vigorously backs Richard, Duke of York's claim to the English throne, convinced York possesses greater legitimacy than King Henry VI of Lancaster. After York's death, Warwick transfers his allegiance to York's son, Edward IV, and engineers his rise to power.

Warwick commands national security and negotiates crucial alliances, proposing a marriage between Edward IV and the French king's sister-in-law. Discovering Edward's secret marriage to Elizabeth Woodville, however, Warwick views this as a profound betrayal and selfish act, prompting his defection from the Yorkists.

Shifting loyalty to the House of Lancaster, Warwick allies with Queen Margaret and publicly vows to restore Henry VI. Privately, he schemes to place his son-in-law, George, Duke of Clarence (Edward IV's brother), on the throne, revealing ambitions beyond factional loyalty. Warwick orchestrates and leads a rebellion against Edward IV, leveraging his formidable influence.

Following his younger daughter Anne Neville's strategic marriage to Edward of Lancaster (Henry VI's son), Warwick successfully deposes Edward IV. Henry VI is reinstated, with Warwick seizing power as regent, wielding authority equivalent to the monarch and marking his political zenith.

His regency falters under military defeats inflicted by resurgent York forces led by Edward IV and Richard III. A critical blow lands when Richard III lures George, Duke of Clarence, away from the Lancastrian cause, severely weakening Warwick's position.

Seeking retreat after these setbacks, Warwick is intercepted and killed by Henry Stafford, Duke of Buckingham, at the Battle of Barnet in April 1471. His demise serves as a final reckoning for the "Kingmaker," reflecting the weight of his complex motivations and political maneuvering.