Henry VI, Part 3 opens with the aftermath of the Battle of St. Albans, where the Yorkists have achieved victory over the Lancastrians. The Duke of York enters Parliament and claims the throne, leading to a confrontation with King Henry VI. A compromise is reached whereby Henry remains king for his lifetime but agrees to disinherit his son Prince Edward in favor of York and his heirs. When Queen Margaret learns of this arrangement, she is furious and raises an army to defend her son’s birthright.

The conflict escalates into full civil war. Margaret’s forces defeat and kill the Duke of York at the Battle of Wakefield, but York’s sons—Edward, George, and Richard—continue the fight. They achieve victory at the Battle of Towton, where King Henry is captured and Edward of York is proclaimed King Edward IV. Henry escapes and flees to Scotland with Margaret and Prince Edward, while Edward IV consolidates his power and marries Elizabeth Woodville, causing tension with his supporter the Earl of Warwick.

Warwick, feeling betrayed by Edward’s marriage, switches sides and allies with Margaret and the exiled Henry VI. With French support, they invade England and briefly restore Henry to the throne while Edward flees to Burgundy. However, Edward returns with an army and reclaims his crown. The final act culminates in the Battle of Tewkesbury, where the Yorkists achieve decisive victory. Prince Edward is killed in battle, Queen Margaret is captured, and Henry VI is murdered in the Tower of London by Richard of Gloucester. The play concludes with Edward IV seemingly secure on the throne, though Richard’s final soliloquy hints at his own future ambitions for the crown.