Edward's brothers, the Duke of Gloucester (the future Richard III) and the Duke of Clarence, supported him in the battle. His opponent was his one-time ally the Earl of Warwick, called "the Kingmaker," who had deposed Edward in favor of his predecessor, the mentally unstable Henry VI.
Two major mistakes helped give the Yorkist army the victory. When Edward's forces drew up the night before, they accidentally took a position much closer to Warwick's army than they intended. Warwick's artillery fired over their heads all night, leaving Edward's forces almost intact.
The next morning, the battlefield was blanketed in fog. The Lancastrian flanks and center mistakenly attacked one another, destroying much of their own army. Warwick was killed on the field and Edward IV returned to the throne.