On 24 August 1453, Thomas Percy, Lord Egremont, assembled a force of men-at-arms and archers perhaps as large as 1,000 strong, intending to waylay Salisbury and his family at Heworth Moor, outside York, as he made for Sheriff Hutton. Salisbury had been attending the wedding of his son Thomas in Tattershall Castle, Lincolnshire, and although his escort would have been smaller, it would have been better armed than Egremont's York craftsmen and tradesmen. Salisbury and his retinue fought them back, arriving unscathed at Sheriff Hutton, but the episode marked the beginning of what was virtually a private war. The bride, Maud Stanhope, was the widow of Lord Willoughby of Eresby, his son would become a Yorkist. Another of the Yorkist party, John Neville, was later Lord Montagu. Maud was due to inherit the manors of Wressle and Burwell from her uncle, Lord Cromwell, who had obtained them from the Percys through litigation. Historian John Sadler argues this was the first incident in the Yorkist/Lancastrian affinities lawless squabble leading to civil war.