Walter Devereux (1387–1419)
Walter Devereux assumed a position in the retinue of Henry IV following the death of his father on 25 July 1402 at the Battle of Pilleth. On 13 December 1402 Sir Edmund Mortimer declared his rebellion against Henry IV, but Devereux stayed loyal to the king. He was probably present at the Battle of Shrewsbury on 21 July 1403, and subsequently was knighted. Sir Walter Devereux was placed on a Commission of array for Herefordshire on 8 September 1403 to raise troops for the defense against the king’s enemies who have lately invaded the realm. It is probable that Devereux was present when Henry IV faced off with a combined Welsh and French force in South Wales during the summer of 1405, but no major battle occurred and the English force had dispersed by October of that year. Devereux remained an important supporter of the efforts to suppress the rebellion in Wales as Prince Henry assumed responsibility for the fight. Walter Devereux would be among 14 men below the rank of baron who would be retained for life by Prince Henry (the future Henry V).
Walter Devereux (1411–1459)
As the King and the Lancasterian party manoeuvred to reverse their losses, lawlessness increased on the Welsh Marches. Walter Devereux, as Constable of Wigmore Castle, was up in arms. In the summer of 1456, he descended on Hereford with the castle's garrison and captured the mayor and justices. Devereux then brought before the justices several local men whom he had the justices condemn to death by hanging. He mustered a force of 2000 archers from Gwent, and marched on the castles at Carmarthen and Aberystwyth, which he took by assault. Afterwards he declared a commission of Oyer and terminer to judge and condemn men whom he believed hostile to York. Among his prisoners were Edmund Tudor, 1st Earl of Richmond, and Robert Rees, Keeper of the Welsh Seal. The king placed Walter Devereux under a recognizance of 1000L on 26 September 1456 to be paid if he didn't immediately turn himself in at Windsor Castle. He, and his son, were also among a group of prominent Herefordshire Yorkists placed under another recognizance of 5000 marks on 2 June 1457 to be paid if they did not turn themselves in for imprisonment at Marshalsea. Devereux, along with Humphrey Stafford and Clement Spryce, were placed under an additional recognizance of 2000 marks on 3 June to be paid if Humphrey Stafford did not turn himself in at Marshalsea. In early 1458 Henry VI granted Walter Devereux a pardon as part of his general effort at reconciliation with the Yorkists, and this was followed by a grant of land in Drogheda in Ireland in 1459.