[citation needed] 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.
Devereux was an important supporter of the efforts to suppress the rebellion in Wales as Prince Henry assumed responsibility for the fight.
This loss of favor may have contributed to the shift of the Devereux family into the retinue of the newly reinstated Earl of March, and ultimately into the affinity of the House of York.
On 2 May 1417 Geoffrey Harley, Richard Hull, and John Monnington granted to John Merbury, and Agnes Crophul, his wife and the heirs of their body: Weobley Castle, and the manors of Weobley, Cotesbach, and Newbold Verdon; the manors of Arnold, Treswell, Hyde, Hemington (in Lockington), Sutton Bonington, Leake, Thrumpton, Braunstone, and the manor and vill of Market Rasen; 3 knights’ fees in Weobley, Straddle (in Vowchurch), Cusop, and Little Marcle in Herefordshire, one and a quarter knights’ fees in Bitterly and Blithelow (in Bishop's Castle) in Shropshire; 60 shillings of rent and the view of frankpledge of Skeffington in Leicestershire; the advowsons in Leicestershire of the priory of Grace Dieu; the churches of Braunstone, Skeffington, and Cotesbach; a fourth part of the church of Bosworth, the advowson of Ludlow in Shropshire; and a fourth part of a water mill in Luton and Wheathampstead (Bedfordshire).
[8] On 20 January 1418 John Walwyn died holding a moiety of the manors of Wellington and Addesore, and left a widow and three underage daughters who became the wards of Walter Devereux.
Walwyn’s widow died in 1419, and the next year the eldest daughter, Elena wife of Richard Monington, proved her full age before the escheator and jurors.