Immediately after Blore Heath the Yorkists were dispersed near Ludlow without a battle, owing to the treachery of a large part of their army. York himself retired to Ireland, Salisbury and Warwick to Calais. The Queen summoned a parliament and Henry gave his assent to a bill of attainder against all the principal Yorkist leaders. At the end of June the Calais exiles made a landing in Kent, seized Sandwich and gathering support entered London on 2 July. Here they were joined by almost all the Yorkist peers and their retainers.

An army allegedly of 30,000 was assembled, and leaving a part of it to blockade meet the King. The court had been in Coventy, but on learning of the Yorkist advance the King moved to Northampton, and here on 10 July, entrenched in a meadow just south of the town, Warwick found the Lancastrian army under the Duke of Buckingham.

The Duke had fewer men than Warwick, but his position was a strong one and his earthworks were lined with artillery. The first attack, on a three section front, was repulsed; it seemed that the position was too formidable a one for any frontal assault to succeed. Indeed, had it not been for the treachery of Lord Grey of Ruthen, holding the left of the Lancastrian line, Warwick might never have had the victory. But when Grey let in the Earl of March (York’s son and later Edward IV), he quickly rolled up the Lancastrian line, allowing Warwick’s attack in the centre to succeed.

The casualties were not high, but as at St. Albans many of the Lancastrian leaders, including Buckingham, Shrewbury and Egremont, were killed.  The King was captured and once more led back to London.