The Yorkist forces began the campaign dispersed over the country. York himself was at Ludlow in the Welsh Marches, Salisbury was at Middleham Castle in North Yorkshire and Warwick was at Calais. As Salisbury and Warwick marched to join the Duke of York, Margaret ordered a force under the Duke of Somerset to intercept Warwick and another under James Tuchet, 5th Baron Audley to intercept Salisbury. Warwick successfully evaded Somerset, while Audley's forces were routed at the bloody Battle of Blore Heath. Before Warwick could join them, the Yorkist army of 5,000 troops under Salisbury were ambushed by a Lancastrian force twice their size under the Baron Audley at Blore Heath on 23 September 1459. The Lancastrian army was defeated, and Baron Audley himself killed in the fighting. In September, Warwick crossed over into England and made his way north to Ludlow. At nearby Ludford Bridge, the Yorkist forces were scattered due to the defection of Warwick's Calais troops under Sir Andrew Trollope.