and parliament. Similar letters were sent to their involved younger sons using stronger terms, warning them that they could eventually suffer forfeiture. Griffiths has suggested that the crown was constrained in its attempts to suppress the law breaking because by now, the king had become incapacitated, and the council ruling in his stead were ill-able to afford alienating fellow magnates whose support might be required in government. Open warfare In retaliation, Sir John Neville raided the absent Earl of Northumberland's house at Catton, in Yorkshire, and all but ruined it. The next day, Richard Percy attacked a house on Neville property. The danger of civil war was intensified when both sides began summoning their retainers to strongholds in the north. On 20 October, the Percy clan had gathered 10,000 men at Topcliffe. Only four miles away, the Neville force was stationed at Sheriff Hutton. After several threats from the king, both sides reached a truce and disbanded their men. However, one chronicler said, "There was no reconciliation, the day of reckoning had merely been postponed." Despite these precautions, it is probable that a few hundred men clashed at Stamford Bridge on 31 October or 1 November 1454, resulting in hundreds dead and more wounded. Lord Egremont was then captured and imprisoned by John Neville. York's protectorate Michael Hicks has described the roots of the Neville's alliance with Richard, Duke of York in 1453 as being based on their having 'common enemies' (for instance, the king's chief minister, Edmund Beaufort, 1st Duke of Somerset) and that this association was significant enough to be 'a coalition of national significance.' Griffiths notes that the parliament of 1453 failed to achieve any accord in the north, and that following the mental collapse of the king, York was made protector and Salisbury Chancellor; this, Griffiths suggests, presented Salisbury with an opportunity for revenge- which the earl took. Salisbury was now in an official position to write to Egremont and his father much more threateningly than the council had attempted the previous year. Northumberland was ordered to appear before the council by 12 June 1454, and his sons on 2 June. The rebellion of the Duke of Exeter During York's Protectorate, Somerset was imprisoned, and the Percys suffered greatly at the hands of the Nevilles. When the king recovered from his illness, York was relieved of power, and Somerset was released and was quick to ally