Backed by wealthy Flemish merchants, in March 1471 Edward's army landed at Ravenspurn. Gathering more men as they went, the Yorkists moved inland towards York. Supporters were initially reluctant to commit; the key northern city of York opened its gates only when he claimed to be seeking the return of his dukedom, like Henry IV seventy years earlier. As they marched south, more recruits came in, including 3,000 at Leicester. Once Edward's force had gathered sufficient strength, he dropped the ruse and headed south towards London. Edward sent Gloucester to entreat Clarence abandon Warwick and to return to the House of York, an offer that Clarence readily accepted. This further shows how frail loyalty was in these times. Edward entered London unopposed and took Henry prisoner; Lancastrian scouts probed Barnet, which lay 19 kilometres north of London, but were beaten off. On 13 April their main army took up positions on a ridge of high ground north of Barnet to prepare for battle the next day. Warwick's army heavily outnumbered Edward's, although sources differ on exact numbers. The battle lasted from two to three hours, and by the time the fog lifted in the early morning, Warwick was dead and the Yorkist had won.