On 22 May 1455, a Yorkist force defeated the royal army at St Albans. Henry VI was captured. Edmund Beaufort, Duke of Somerset, was killed.

The battle was small beside later fighting in the Wars of the Roses, but its consequences were serious. It showed that the king’s government could no longer contain the rivalries around it. Politics had reached the point where noblemen came armed, negotiations failed, and the king’s control could be settled in the streets of a town.

Henry VI’s rule had been weak for years. England had lost much of what it once held in France, royal finances were strained, and the king’s authority depended heavily on those around him. Henry’s periods of mental collapse made the problem worse. Power gathered around courtiers, councillors and great nobles who claimed to act in the king’s name.

Richard, Duke of York, was the most dangerous of those nobles. He was close to the throne by blood and had held high office, but by 1455, he was outside the circle of power. His complaint centred on the men who controlled access to Henry, especially Somerset. York presented his cause as a demand for better government and the removal of corrupt or failed advisers. It was still possible to describe this as loyalty to the crown. That became harder once armed men were moving towards St Albans.

The royal army held the town. Henry VI was there, along with Somerset and other Lancastrian lords. York approached with his allies, including the earls of Salisbury and Warwick. Messages were exchanged. York wanted Somerset to be handed over. The king’s side refused.

The fighting that followed was cramped and local. The royal forces blocked the main approaches, and the Yorkists struggled to break in. Warwick then found a way through the town’s defences, and his men forced their way into St Albans through gardens and side routes. Once the Yorkists were inside, the royal position collapsed quickly.

Somerset was killed. So were other leading Lancastrian nobles, including the Earl of Northumberland and Lord Clifford. Henry VI was wounded and captured by the Yorkists.

That fact mattered most. The king had not been overthrown, but he had been captured. York could now claim to act through Henry while holding the king’s person under his control. The battle removed some of York’s enemies. Still, it did not solve the deeper problem of a monarchy too weak to command obedience from its own political class.

St Albans did not make the Wars of the Roses inevitable in every detail. Later choices still mattered. But it changed the way politics is done. A dispute over counsel, office and access to the king had turned into armed violence. Once that had happened, it was harder to pretend that the old machinery could simply start working again.