His father, Walter, died in 1197, and as a member of the retinue of William de Braose this probably occurred in France during May 1197 at the assault on the castle at Milly-sur-Thérain.
Walter Devereux's lands passed into the King's hands and were placed in the custody of the sheriff of Hereford, William de Braose, 4th Lord of Bramber.
[d] About 1199 Stephen Devereux was placed in the retinue of William Marshal for training as a knight, and over the years came ‘to be trusted for his cool-headed judgement’ and a member of the earl's inner circle.
The Justiciar delivered three letters in January 1208 summoning John of Earley, Jordan de Saqueville, and Stephen Devereux to appear before the king in England within 15 days, or suffer the loss of all their lands.
[13][14] The three decided to stand fast for their lord, William Marshal, and sent to seek aid from Hugh de Lacy, 1st Earl of Ulster, to resist the forces assaulting them.
He informs him that the earl's pregnant wife was besieged in Kilkenny castle, and that a bloody battle had been fought there causing the death of Stephen Devereux and John of Earley.
[19][20][e] By the summer of 1208, William de Braose, 4th Lord of Bramber, had fallen out of favour with King John and fled to his friend, the earl of Pembroke, in Ireland.
[23][24][25] John raised a great army to bring to Ireland, and William Marshal rushed to England to renew his submission and vow no further support for de Braose.
Marshal seized this opportunity to make a gesture of support for the king,[27] prompting the release of the earl's men and restoration of Stephen Devereux's estates.
[f] Stephen Devereux participated in the King's expedition to Poitou in France during the first part of 1214, and is present for the conquest of Anjou and the final withdrawal following the Battle of Bouvines.
King John was forced to offer tax concessions to induce participation, but many leading barons still were not involved directly choosing to send proxies instead.
[31] William Marshall and Stephen Devereux stood firm with the King, and were deeply involved in the negotiations resulting in Magna Carta,[32] which John signed at Runnymede on 15 June 1215.
On 4 July 1215 King John wrote in a royal writ describing Stephen as ‘our dear and faithful’ when ordering a quittance of an annual render to Hereford Castle of 32 gallons of honey from Devereux's manor of Ballingham.
The earl of Pembroke and Stephen Devereux remained faithful to the King, but at the time of John's death on 18 October 1216 two thirds of England was in open rebellion[34] and a French army had landed at Sandwich, county Kent, to support the claim of their Prince (who became Louis VIII of France) to the throne.
The French claimant, Prince Louis, was forced to break off his siege of Dover,[37] and following the destruction of his reinforcements at the naval battle of Sandwich on 24 August 1217, abandoned England and his claim to the throne.
[41] In June 1219 Stephen Devereux was assigned as inquisitor along with William Cantilupe Senior, Walter Muscegros, Gilbert Talbot, and Hugh Rigal (clerk) with instructions to travel through Hereford County reviewing the use of land, and insuring that all was being done by grant of the king.
The following year Stephen was appointed a justice of gaol delivery for Hereford[l] During 1219 Devereux confirmed the grant of his father and himself of the whole church of Lyonshall to the canons of Pyon, and expressed his regret that the urgency of his affairs prevented him from tendering his gift in person.
[47] On 20 February 1223 Prior Ralph of Wormsley promised not to alienate or sell any of the lands or possessions which they held of the gift of Stephen Devereux without his assent.
Devereux had further litigation in August 1221 against Isabel, Aldith, and Cecily, daughters of Simon Bocha, in a plea of assize of mort d’ancestor by Gerard le Pele.
On 27 April 1223 from the Court at St. Albans an order to the sheriffs of Essex and Hertfordshire to cause the demand that the King makes from Stephen d’Évreux by summons of the Exchequer for several scutages from his land of Trumpington to be placed in respite until upon his next account.
Additional lands included Clehonger, and Staunton-on-Wye in Herefordshire; Crowle in the Royal Forest of Feckham, and Staunton in Worcester; Guiting and Oxenhall in Gloucestershire; Trumpington in Cambridgeshire: and Bosnormand (Eure) in the Évreçin, Normandy.
In 1242, Isabel Devereux held in Magene Album (Whitchurch maund in the parish of Bodenham) of the Honor of Weobley 2 hides from Roger Pichard by knight's service in the Hundred of Brokesesse in Hereford.
[24] On 21 February 1244 his widow, gave to the Hospital of St. Ethelbert for the souls of herself and her two husbands "unam ladum bladi" at the Feast of St. Andrew during her life to be received at her house in Frome.