Battle of Ferrybridge.
With the Lancastrians taking up position north of the river Aire, and lord Clifford holding and destroying the only crossing at Ferrybridge, the earl of Warwick had to fight to take the bridge and make repairs on 27 March. The following morning Clifford launched a surprise attack, mortally wounding Warwick’s second-in-command, John Radcliffe lord Fitzwalter. Warwick, despite himself receiving an arrow wound in the leg, rallied his forces and crossed the bridge. Clifford once again destroyed it. Warwick sent his uncle, lord Fauconberg, upriver to outflank Clifford. Clifford and his men retreated, but were caught in the open by Fauconberg. In the following struggle, Clifford and John Nevill (the earl of Westmorland’s brother and the man who possibly betrayed the duke of York’s forces at Wakefield) were killed. (Philip Haigh, The Military Campaigns of the Wars of the Roses, p 58-9)
According the Edmund Halle, writing much later, also killed at Ferrybridge was ‘the Bastard of Salisbury’, Warwick’s half brother. I haven’t found any other reference to him and I’m not sure he existed.