But his plot was already successful before he reached the scene of operations. The Yorkshire rebels beat the royalist army at the battle of Edgecott (July 6, 1469). A few days later Edward himself was captured at Olney and put into the earl's hands. Many of his chief supporters, including the queen's father, Lord Rivers, and her brother, John Woodville, as well as the newly-created earls of Pembroke and Devon, were put to death with Warwick's connivance, if not by his direct orders. The king was confined for some weeks in the great Neville stronghold of Middleham Castle, but presently released on conditions, being compelled to accept new ministers nominated by Warwick. The earl supposed that his cousin's spirit was broken and that he would give no further trouble. In this he erred grievously. Edward vowed revenge for his slaughtered favourites, and waited his opportunity. Warwick had lost credit by using such underhand methods in his attack on his master, and had not taken sufficient care to conciliate public opinion when he reconstructed the government. His conduct had destroyed his old reputation for disinterestedness and honesty.
In March 1470 the king seized the first chance of avenging himself. Some unimportant riots had broken out in Lincolnshire, originating probably in mere local quarrels, but possibly in Lancastrian intrigues. To suppress this rising the king gathered a great force, carefully calling in to his banner all the peers who were offended with Warwick or, at any rate, did not belong to his family alliance. Having scattered the Lincolnshire bands, he suddenly turned upon Warwick with his army, and caught him wholly unprepared. The earl and his son-in-law Clarence were hunted out of the realm before they could collect their partisans, and fled to France; Edward seemed for the first time to be master in his own realm.
But the Wars of the Roses had one more phase to come. Warwick's name was still a power in the land, and his expulsion had been so sudden that he had not been given an opportunity of trying his strength. His old enmity for the house of Lancaster was completely swallowed up in his new grudge against the king that he had made. He opened negotiations with the exiled Queen Margaret, and offered to place his sword at her disposition for the purpose of overthrowing King Edward and restoring King Henry. The queen had much difficulty in forcing herself to come to terms with the man who had been the bane of her cause, but finally, was induced by Louis XI. to conclude a bargain. Warwick married his younger daughter to her son Edward, prince of Wales, as a pledge of his good faith, and swore allegiance to King Henry in the cathedral of Angers. He then set himself to stir up the Yorkshire adherents of the house of Neville to distract the attention of Edward IV. When the king had gone northward to attack them, the earl landed at Dartmouth (Sept. 1470) with a small force partly composed of Lancastrian exiles, partly of his own men. His appearance had the effect on which he had calculated. Devon rose in the Lancastrian interest; Kent, where the earl's name had always been popular, took arms a few days later; and London opened its gates. King Edward, hurrying south to oppose the invader, found his army melting away from his banner, and hastily took ship at Lynn and fled to Holland. He found a refuge with his brother-in-law and ally Charles the Bold, the great duke of Burgundy.