Guillaume V DE BRIOUZE, Lord De Radnor, Brecon Et Abergavenny 
- Born: Abt 1200, Brecon Castle, Brecon, Wales
- Marriage: Eve MARSHAL 
- Died: 2 May 1230, Ystrad Fflur, , Wales about age 30
Other names for Guillaume were William, DE BRAOSE and DE BREWES.
Sources and Notes
Réginald († v. 1228), lord de Radnor, Brecon et Abergavenny
× Grecia Brewire, mère de Guillaume
× Glawdys Ddu, fille illégitime de Llywelyn le Grand
Guillaume (V) († 1230), lord de Radnor, Brecon et Abergavenny × Éva, fille de Guillaume le Maréchal , 1er comte de Pembroke
... Guillaume (V) († 1230), son fils et héritier, est pendu en 1230 par Llywelyn le Grand pour adultère avec sa femme Jeanne d'Angleterre. Il laisse quatre filles, toutes mariées à d'importantes figures des marches galloises, entre lesquels le patrimoine est divisé."
"William de Braose (c. 1197 - 2 May 1230) was the son of Reginald de Braose by his first wife, Grecia Briwere. He was an ill-fated member of a powerful and long lived dynasty of Marcher Lords.
William de Braose was born in Brecon, probably between 1197 and 1204. The Welsh, who detested him and his family name, called him Gwilym Ddu, Black William. He succeeded his father in his various lordships in 1227, including Abergavenny and Builth.
He was captured by the Welsh forces of Prince Llywelyn the Great, in fighting in the commote of Ceri near Montgomery, in 1228. William was ransomed for the sum of £2,000 and then furthermore made an alliance with Llywelyn, arranging to marry his daughter Isabella de Braose to Llywelyn's only legitimate son Dafydd ap Llywelyn.
However on a later visit to Llywelyn during Easter 1230 William de Braose was found in Llywelyn's private bedchamber with Llywelyn's wife, Joan, Lady of Wales.
The Chronicle of Ystrad Fflur's entry for 1230 reads:
"In this year William de Breos the Younger, lord of Brycheiniog, was hanged by the Lord Llywelyn in Gwynedd, after he had been caught in Llywelyn's chamber with the king of England's daughter, Llywelyn's wife".
Llywelyn had William publicly hanged on 2 May 1230, possibly at Crogen, near Bala, though others believe the hanging took place near Llywelyn's palace at Abergwyngregyn.
With William's death by hanging and his having four daughters, who divided the de Braose inheritance between them and no male heir, the titles now passed to the junior branch of the de Braose dynasty, the only male heir was now John de Braose who had already inherited the titles of Gower and Bramber from his far-sighted uncle Reginald de Braose.
William married Eva Marshal, daughter of William Marshal, 1st Earl of Pembroke. They had four daughters:
1.Isabella de Braose (born c. 1222), wife of Prince Dafydd ap Llywelyn
2.Maud de Braose (born c. 1224 - 1301), wife of Roger Mortimer, 1st Baron Wigmore another very powerful Marcher dynasty.
3.Eleanor de Braose (c. 1226 - 1251), wife of Humphrey de Bohun and mother of Humphrey de Bohun, 3rd Earl of Hereford.
4.Eva de Braose (c. 1227- July 1255), wife of William de Cantelou.
William's wife Eva continued to hold de Braose lands and castles in her own right, after the death of her husband. She was listed as the holder of Totnes in 1230, and was granted 12 marks to strengthen Hay Castle by King Henry III on the Close Rolls (1234\endash 1237).
"WILLIAM de Briouse (-hanged 2 May 1230). A manuscript which narrates the descents of the founders of Lanthony Abbey names "Willielmus de Brews quartus" as son of "Reginaldus de Brews" and his wife "filiam domini Willielmus de la Bruere". The Red Book of the Exchequer records "Willelmus de Braosa" holding one knight´s fee "in Eadburgetone" in Kent in [1210/12]. Henry III King of England granted "honore de la Cnappe et de…Bremble", relinquished by "Reginaldus de Braosa", to "Willelmo de Braosa filio et heredi suo" dated 7 Aug 1218. "Willelmi de Braosa" gave homage to King Henry III for lands "que Reginaldus de Braosa pater suus de rege tenuit in capite" dated 13 Jul 1228. The Annals of Tewkesbury record that "W. de Breuse filius Reginaldi de Breuse" was captured by "Lewelinum" in 1228. The Chronicle of the Princes of Wales records that "William Bruse was hanged by Llywelyn son of Iorewerth, having been caught in the chamber of the prince with the princess Jannet, daughter of King John and wife of the prince" in 1230. The Annals of Dunstable record that "Willelmus de Brause" was captured and hanged by "Leulino" in 1230. The Annals of Tewkesbury record that "Lewelinus princeps Norwalliæ" captured and hanged "Willelmum de Breuse filium Reginaldi" after Easter in 1230. The Annals of Margan record that "Lewelinus" captured and killed "Willelmum de Brewsa juniorem" in 1230, adding that it was partly motivated by his old hatred of "progenitorum suorum…Willelmi de Brewas senioris et Matildis de Sancto Walerico uxoris suæ" who had killed many Welsh people, which confuses William de Briouse, son of Reynold, with his cousin William de Briouse, son of William (see above).
m EVA Marshal, daughter of WILLIAM Marshal Earl of Pembroke & his wife Isabel Ctss of Pembroke (-before 1246). The Chronicle of Tintern Abbey, Monmouthshire records that "quinta filia…Willihelmi Marescalli…Eva" married "Willielmo de Brewes". If it is correct that Eva was her parents´ fifth daughter, she would have been born after . A manuscript which narrates the descents of the founders of Lanthony Abbey names "Willielmus de Brews quartus" married "Evam filiam domini Willielmi Mareschalli". Her parentage and marriage are confirmed by a letter from "L. princeps" to "domino W. Marescallo comiti Penbrochiæ" assuring him that he still wishes the proposed marriage between "neptem vestram et filium nostrum David" to take place. King Henry III granted "in villa de Haya" to "Eve de Braose" dated 6 Jun 1232.
William & his wife had four children:
i) ISABEL de Briouse (-1248)
ii) MATILDA de Briouse (-before 23 Mar 1301). ...
iii) EVA de Briouse (-20 Jul 1255). ...
iv) ELEANOR de Briouse (-bur Llanthony Priory, Gloucester)."
Guillaume married Eve MARSHAL , daughter of Guillaume LE MARECHAL, 1st Earl Of Pembroke  and Isabelle DE CLARE . (Eve MARSHAL  was born in 1203 in Pembroke Castle, Pembroke, Wales and died in 1246 in , , England.)