a small Hertfordshire town north of London, Edward led the House of York against Richard Neville, 16th Earl of Warwick, and the House of Lancaster, which backed Henry VI for the throne. The battle began in a thick fog at dawn. While the main forces struggled, John de Vere, 13th Earl of Oxford, and his Lancastrian troops routed the Yorkists under Lord William Hastings, chasing them up to Barnet. On their return to the battlefield, Oxford's men were erroneously shot at by his allies commanded by John Neville, 1st Marquess of Montagu. The Lancastrians lost the battle as cries of treason spread through their line and many abandoned the fight. While retreating, Warwick was killed. Historians regard the battle as one of the most important clashes in the Wars of the Roses, bringing about a decisive turn in the fortunes of the two houses. (Full article.