At this point in the civil war, the Lancastrians were on equal terms with the Yorkists, having eliminated the Duke of York from the scene at the Battle of Wakefield and been victorious at the second Battle of St Alban's. However, Richard Neville, Earl of Warwick, "the Kingmaker", controlled London and had proclaimed the eldest of York's sons as King Edward IV of England. It was Edward himself who decided to take the initiative and march north in the hope of inflicting a final defeat on his rival, King Henry VI of England. Henry, a pious and peace-loving man, took no part in any military decisions, but allowed his queen, Margaret of Anjou, complete freedom to employ her battle commanders, chief of whom was Lord Clifford, on his behalf.
It is thought that 50,000, or perhaps even 80,000 men fought, including 28 Lords (almost half the peerage).
The battle was long and hard-fought, made no easier for either side by the blizzard conditions which prevailed. The decisive moment came in the middle of the day, when the Yorkist reinforcements arrived, led by the John Mowbray, 3rd Duke of Norfolk. The Lancastrians retreated in disarray, resulting in a near-massacre. The death in battle of Lord Clifford, Queen Margaret's most experienced commander and right-hand man, was a serious blow from which the Lancastrians would take years to recover. Margaret and Henry fled north to Scotland, while those Lancastrian lords who were not killed or dispossesed were forced to make peace with Edward.