Not many days before the second battle of St. Albans, the young Edward of York had routed the Lancastrians of Wales at the battle of Mortimer's Cross, in Herefordshire. He had then set out to march on London; on the way he was met by Warwick, who brought the news of his own defeat, and of the queen's approach to the capital. But, learning that she had not yet entered its walls, they marched night and day, and threw themselves into the city just as its gates were opening for surrender. [Sidenote: =Retreat of the queen.=] The arrival of the heir of York and his victorious troops turned the fortune of the war. Margaret's army had in great part dispersed to plunder the Midlands, for the Northerners had vowed to treat every man south of the Trent as an enemy. When Duke Edward advanced they gave way before him, and retreated towards York, wasting the country behind them on all sides. [Sidenote: =Edward proclaims himself king.=] The slaughter of Wakefield and St. Albans, and more especially the ruthless execution of prisoners which had followed each battle, had driven the Yorkists to a pitch of anger which they had not felt before. There was no longer any talk of making terms with Henry VI., and leaving him the crown. Warwick and the other nobles of his party besought the young duke to claim the crown, as the true heir of Richard II., and to stigmatize the three Lancastrian kings as usurpers. Edward readily consented, and proclaimed himself king at Westminster on his hereditary title, and without any form of election or assent of Parliament. [Sidenote: =Battle of Towton.=] But the new king had to fight for his crown before he could wear it. He and Warwick pursued the queen's army over the Trent, and caught it up at Towton, near Tadcaster, in Yorkshire. Here was fought the greatest and fiercest of the battles of the Wars of the Roses. Both parties were present in full force; the South and Midlands had rallied round Edward IV. in their wrath at the plundering of the Northumbrians. The Lancastrians of Wales and the Midlands had joined the queen during her retreat. The chroniclers assert that the two armies together mustered nearly a hundred thousand men--an impossible figure, but one which vouches for the fact that Towton saw the largest hosts set against each other that ever met on an English battle-field. [Sidenote: =Slaughter of Lancastrian leaders.=]