During his father’s lifetime, Walter Devereux was established in the ancestral Devereux manors of La Fenne (Bodenham) and Whitchurch Maund.[7] Large parts of Bodenham had been in the possession of his family since the Domesday Survey when they were held by a William Devereux. As a retainer of Humphrey de Bohun, 3rd Earl of Hereford,[8] he probably participated in the private feud his lord had with the earl of Gloucester.
Walter acknowledged a debt of 77s 4d to Laurence Lodelawe on 8 May 1289.[9] Devereux was a knight prior to 1290 when he witnessed his father's grant to the Priory and Convent of St. Guthlac of Hereford.[10] He was listed among the knights witnessing Roger Ragun’s bond to pay John Pennebruge 40s yearly for life on 12 Nov 1291.[11] Devereux was probably knighted for participation in the campaigns against the Welsh that his father, William Devereux, was involved in.
On 26 May 1296 Letters of Protection were issued for Walter Devereux who was to be serving in Scotland with Humphrey de Bohun, 3rd Earl of Hereford.[12] Walter Devereux was identified as holding over 20L in lands and rents in Herefordshire in 1297, and as such was summoned to perform military service beyond the seas.[13] He was instructed to muster at London on 7 July 1297. He fought under Humphrey de Bohun at Falkirk. A Walter de Bodenham was listed among the men that Edward I led in the invasion of Scotland in 1298, and who fought at the Battle of Falkirk.[14] He was identified among the horse belonging to the royal household, and as possessing a 'runicum' (horse of lesser grade) which was spotted iron-grey with a white right front foot and valued at 12 marks.
At the inquiry post-mortem on 7 January 1299 following the death of Humphrey de Bohun, 3rd Earl of Hereford, Walter Devereux held one knight fee of the honor of Brecknock.[15]
On the subsidy rolls for 1303 Walter Devereux is shown holding 1/2 fee in Bodenham, county Herefordshire. He was assessed 20 shillings.[16]
In 1304 he was listed as holding in custody some of the lands of the under-age Roger Mortimer, the future Earl of March. Roger was the son of Edmund Mortimer, 2nd Baron Mortimer, who had died on 17 July 1304, and his widow, Margaret, Baroness de Mortimer, had filed suit against Hugh de Aldytheleye and Isolda his wife over various parts of the estate.[17] When being summoned to court on a follow up document dated 29 Sep 1305, Walter Devereux was identified as having died.[18]
A grant in 1317 by Thomas Swonild to Thomas de Hueton and his sons, Walter and Hugh, described the croft as lying in the town of la More between the land late of Sir Walter Devereus and the Tyne brook.[19] This was witnessed by his son, John Devereux.