Sir William ap Thomas, The Blue Knight of Gwent

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William ap Thomas

Also Known As: "Blue Knight of Gwent", "Y Marchog glas o Went", "The Blue Knight of Gwent", "Gwilym ap Thomas", "Blue Knight"
Birthplace: Raglan, Monmouthshire, Wales (United Kingdom)
Death: 1446 (61-71)
London, Middlesex, England (United Kingdom) (beheaded)
Place of Burial: Abergavenny, Monmouthshire, Wales
Immediate Family:

Son of Sir Thomas ap Gwilym, Kt. and Mawd Morley
Husband of Elizabeth de Bluet, Heiress of Raglan and Gwladus verch Dafydd Gam
Partner of Cari Ddu
Father of Elsbeth ferch William; Margred Herbert; William Herbert, 1st Earl of Pembroke; Sir Richard Herbert, of Coldbrook; Elsbeth verch William and 7 others
Brother of Tudful verch Thomas; Hywel y Bwlch ap Thomas; Margred verch Thomas; Hywel ap Thomas Lord of Perth-Hir; Robert ap Thomas, Rector of Llanfihangel and 3 others
Half brother of N.N. Godwin; Dafydd ap Thomas and Ieuan ap Thomas

Occupation: Fought at the Battle of Agincourt in 1415; William retained Raglan as a tenant of his stepson, James Lord Berkeley; in 1425, Lord Berkeley agreed ap Thomas could hold Raglan Manor the rest of his life., The Blue Knight of Gwent
Managed by: Anne Brannen
Last Updated:

About Sir William ap Thomas, The Blue Knight of Gwent

See Peter Bartrum, (January 31, 2018; Anne Brannen, curator)

See Peter Bartrum, (December 7, 2017; Anne Brannen, curator)

William ap Thomas (died 1445) was a member of the Welsh gentry family that came to be known as the Herbert family through his son William Herbert, 1st Earl of Pembroke and is an ancestor of the current Earls of Pembroke.

Raglan manor, attained through marriage through heiress Elizabeth Bluet, was greatly expanded by William and his son, William Herbert, into the well-fortified Raglan Castle, one of the finest late medieval Welsh castles.

William served King Henry V of England during his first French campaign and in numerous subsequent capacities and was knighted in 1426. He fought in the Battle of Agincourt.


In 1410, he and Thomas, lord Berkeley (brother of Sir James Berkely, whose widow he married) feloniously seized a Genoese ship laden with wine, for which they had to make restitution. (Bradney, History of Monmouthshire, vol. 1 p. 5, 6)

Links Family Links Spouses/Children: 1. Elizabeth BLUET Heiress of Raglan 2. Gwladus FERCH DAFYDD Margaret HERBERT+ William HERBERT K.G., 1st Earl of Pembroke+ 3. Cari DDU John HERBERT of Itton Sir William AP THOMAS of Raglan

Born: Abt 1377, Plas yn-y-berth-hir (Perth-hir), Monmouthshire, Wales Married (1): After 1405, 3rd husband 1st wife 411,2223,10607 Married (2): After 1415, 2nd husband 2nd wife 2223,10491 Married (3): Before 1418, No Marriage 411 Died: 1446, Raglan Castle, Usk, Monmouthshire, Wales 2223,10491 Buried: Priory Church, Abergavenny, Monmouthshire, Wales

  Another name for William was Sir William ap Thomas HERBERT of Raglan. 411,2223,10491,10607

General Notes:
Sir William Thomas, called "Y Marchog Glas o Went" ("The Blue Knight of Gwent"), of Raglan, Mon, the (feudal) Lordship of which he bought from 1st Lord (Baron) Berkeley; knighted 1415; married 1st his former employer Elizabeth (to whom he had been steward), daughter and heiress of Sir John Bluet, of Raglan, and widow of Sir James Berkeley (by whom she was mother of the 1st Lord (Baron) Berkeley; married 2nd, as her 2nd husband, Gwladus (died 1454), daughter of Dafydd Gam (killed at Agincourt) and widow of Sir Roger Vaughan, of Tretower (also killed at Agincourt), and died 1446. [Burke's Peerage]


Built the "Great Tower" of Raglan Castle.


Copied from Herbert, George biography, 88.1911

Thomas’s fifth son, William or Gwilim ap Thomas, who died abt 1446, was the first man of the family to make any figure in history. This Gwilim ap Thomas was steward of the lordships of Usk and Caerleon under Richard, duke of York. Legend makes him a knight on the field of Agincourt, but his knighthood belongs to the year 1426. He appears to have married twice, his first wife being Elizabeth Bluet of Raglan, widow of Sir James Berkeley, and his second a daughter of David Gam, a valiant Welsh squire slain at Agincourt. Royal favour enriched Sir William, and he was able to buy Raglan Castle from the Lord Berkeley, his first wife’s son, the deed, which remains among the Beaufort muniments, refuting the pedigree-maker’s statement that he inherited the castle as heir of his mother Maude daughter of Sir John Morley.


The following material was copied from Jane Williams Flank, World Connect db=jwflank,

Other sources:

Welsh Genealogies AD 1400-1500, Vol 3 - pp 86, 104; Vol 4 - pg 202; Vol 6 pp 378, 422, 425, 439; Vol 8 pg 622 (FHL # 6025561) Wales Visitation, Vol 1 - pp 292-3, 295, 312; Vol 2 - pg 165; Vol 5- pp 740, 785. 790 (FHL 942,9 D2fw) Peerage (Burke), 1876 - pg 923 (FHL 942 D22bup) Peerage (Burke), 1967 - pg 2039 (FHL 942 D22bup) Baronagium Genealogicum, Vol 3 - pg 263 (FHL #0164680 Buckingham Co History, Vol 1 - pg 297 (FHL Q942.575 H2li) Commoners, Vol 2 - pg 24; Vol 4 - pp 552fn, 730 (FHL 942 B2bc) Miscellanea Genealogica 5s, Vol 5 - pg 188 (FHL 942 B2m) Archaeologica Cambrensis 5s, Vol 1 - pg 288 (FHL 942.9 B2c) Wallop Family, vol2 - pg 422 (FHL Q942.242 W159w) Derbyshire Archaelogical Journal, Vol 31 - p 204 (FHL 942.51 B2a) Monmouthshire History, Vol 1 - pp 47, 165, 185, 189, 285; Vol 2 - pg 12, Vol 4 - pg 300 (FHL #0990053-54) Brecknockshire, Vol 2 - pg 394 (FHL Q942.965 H2j) Carmarthenshire Sheriffs - pp 5, 34, 65 (FHL 942.98 D2b) Dorset History Society Proceedings, Vol 66 - pg 83 (FHL 942.33 C4d) Montgomeryshire Collections, Vol 2 - ped; Vol 3 pg 341; Vol 5 pg 159 (FHL 942.94 C4mp) Robertson et Durdin -tb198 (FHL 929.242 R545r) Monmouthshire Historical Tour - pp 148, 171 (FHL 942.43 H2cw) Wales County Annuals - pp 777 (FHL #0832242) Herberts of Wilton - pg 2 (FHL 929.242 H414) Morgan and Blamorgan Geneologies - pp 195, 280, 306 (FHL 942.97 D2c) Earl of Pembroke - ped (FHL #104324) Herbert Pedigrees - pg 4 (FHL #8026552 it3-4) Dorst Antiquarian Club, Vol 66 - pg 83 (FHL 942.33 C4d) Chepstow Catle Annals - pp 178, 270 (FHL 942.43/C1 D2m) Herbert Correspondence - ped (FHL 942.9 B4b #21)

The house of Herbert is of somewhat dubious origin. There are three accounts of its prime ancestor. 1) the race springs from Herbert, a natural sone of Henry I of England (this version has never met with acceptance), 2) gives Henry Fitz Herbert, Chamberlain to Henry I as prime ancestor, 3) henry Fitz Herbert, the Chamberlain was son of Herbert, son of Godwin, son of Elfryd, and that the said Herbert married the daughter of Godwin, Earl of Kent.

WALES AND ENGLISH POLITICS. Stability of government in England was in essence bad news for Wales, for in such a context the Welsh were frozen into their subordinate social position. However the outbreak of civil war in England from 1455, and the fact that both Yorkist and Lancastrian factions in that civil war needed to optimise their support in Wales created a more favourable context for Welshpolitics. The objective of both Yorkists and Lancastrians was best achieved by nurturing Welsh leaders capable of mobilising the native Welsh to their respective cause. That in turn implied that the Welsh - throughout the Wars of the Roses - were strongly placed to bargain for the amelioration of their social subjection. The ending of the first stage of the civil war in a Yorkist victory in March 1461 highlighted that reality for Sir William Herbert was entrusted with the role of chief justice and chamberlain of South Wales as well as a host of other responsibilities and lands. In 1463 his role was extended into North Wales with his appointment as chamberlain and chief justice of Meirioneth. In February 1462 he also secured custody of the five year old Henry Tudor (son of Edmund Tudor) whom he had captured at Pembroke in 1461. Henry was thus reared in the Welsh speaking Herbert household. Herbert's responsibilities and powers were further enhanced during the late 1460's by which time he dominated Welsh politics. His role ended abruptly in July 1469 when he was executed following defeat and capture by Lancastrian forces at the battle of Banbury. See : Fig 48 Monument of Sir William ap Thomas of Raglan p238. Also : Fig 49 Seal of Sir William Herbert of Raglan p239. In : M.P.Siddons - The Development of Welsh Heraldry Vol 1, National Library of Wales, Aberystwyth 1993. THE STRUGGLE FOR WELSH BARDIC SUPPORT. Both the Yorkist and Lancastrian camp were strongly represented in Wales. Richard duke of York was a Marcher lord who secured more than half his annual income from Wales - £3,430 from Wales as compared to c £3,230 from England. Edmund and Jasper Tudor were the sons of Owain Tudur and half brothers of Henry VI. Edmund earl of Richmond was sent to Wales to strengthen the royal position, and his son Henry Tudor was born at Pembroke castle in January 1457, two months after his fathers death. In that context Jasper Tudor as earl of Pembroke assumed the role vacated by his brother. Both sides recognised the importance of bardic support and thus patronised the bards. Owain Tudur and his family had long been patrons - a tradition sustained by Jasper. For the Yorkists William Herbert played a central role in securing bardic support. As a consequence, during the Wars of the Roses the bards sought to promote Welsh interests through both of the contending factions. A WELSH UCHELWR WITHIN THE YORKIST CAMP. William Herbert was the anglicised name of William ap William a descendant of the leading Brecon family. His grandfather was Dafydd Gam, an opponent of the Owain Glyn Dwr revolt who died at Agincourt in 1415. Dafydd's son, William ap Thomas purchased the Raglan estate in 1430. William Herbert built on that foundation being admitted to the House of Lords and elevated to a Knight of the Garter. In 1466 the king created the lordship of Raglan, (the last Marcher lordship created in Wales) in appreciation of services rendered by Herbert. THE WAR OF THE ROSES AND BRYTHONIC TRADITION. In keeping with Brythonic tradition a great feast was held at Raglan prior to departure for Banbury. On the eve of battle, when disagreement between Herbert and the earl of Devon led to the withdrawal of the latter from the scene of battle - traditional visions of the Welsh inflicting defeat on their Saxon enemies were to strongly motivate the forces under Herbert. Despite the fact that this was a battle in an 'English' civil war, the Welsh forces were motivated by long established Brythonic imagery.

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William ap Thomas was the member of a minor Welsh gentry family and was responsible for beginning the construction of Raglan Castle as we recognize it today. He obtained Raglan through his marriage to Elizabeth Bloet, widow of Sir James Berkeley shortly after 1406. When Elizabeth died in 1420, ap Thomas retained Raglan as a tenant of his step-son James, Lord Berkeley, and in 1425 Lord Berkeley agreed that he could continue to hold Raglan for the duration of his life.

William married for a second time, and chose another heiress, Gwladus. She was the daughter of Sir Dafydd Gam and the widow of Sir Roger Vaughan. Both these men had been part of the Welsh contingent that fought with King Henry V in France, and both were at the battle of Agincourt, where William ap Thomas had also fought. In 1426, ap Thomas was knighted by Henry VI, becoming known to his compatriots as Y marchog glas o Went (the blue knight of Gwent). Gradually he began to establish himself as a person of consequence in south Wales.

As early as 1421 William held the important position of steward of the lordship of Abergavenny, and later became chief steward of the duke of York's estates in Wales, 1442-43. Other positions held by Sir William included that of sheriff of Cardiganshire and Carmarthenshire, to which he was appointed in 1435, and his position as sheriff of Glamorgan followed in 1440. Although he became one of the followers of Richard, duke of York, and a member of the duke's military council, Sir William's sphere of influence was largely confined to south Wales.

By 1432 William was in a position to purchase the manor of Raglan from the Berkeleys for about L667 and it was probably from this time that he began to build the castle as we know it. His building programme eventually swept away most of the original structures. The principal buildings surviving from this time are the Great Tower (left) a self-contained fortress in its own right, together with the south gate, both equipped with gunloops. He also raised the hall, though later largely rebuilt, and part of the service range beyond. Two sources indicate that William ap Thomas was the builder of the keep. One of which is a contemporary poem praising ap Thomas, mentioning the tower at Raglan which "stands above all other buildings." There is also a reference to Sir William Thomas' tower from a family chronicle written by Sir Thomas Herbert of Tintern.

William ap Thomas died in London in 1445, and his body was brought back to Wales to be buried in the Benedictine priory church at Abergavenny. His wife Gwladus (the star of Abergavenny), as she was hailed by the poet Lewys Glyn Cothi, died in 1454. William was succeeded by his eldest son, another William (d.1469) who took the surname Herbert. 411

  Marriage Information:

William married Elizabeth BLUET Heiress of Raglan after 1405 in 3rd husband 1st wife 411,2223,10607. (Elizabeth BLUET Heiress of Raglan was born about 1373 in Raglan Castle, Usk, Monmouthshire, Wales and died before 1415 2223.)

   Marriage Information:

William also married Gwladus FERCH DAFYDD, daughter of Dafydd "Gam" AP LLEWELYN and Gwenllian FERCH GWILYM, after 1415 in 2nd husband 2nd wife 2223,10491. (Gwladus FERCH DAFYDD was born about 1385 in Peutun, Llan Ddew, Breconshire, Wales and died in 1454 2223.)

   Marriage Information:

William also married Cari DDU before 1418 in No Marriage 411. (Cari DDU was born about 1400 in Troy Parva, Michel Troy, Monmouthshire, Wales.)

William ap Thomas (died 1445) was a Welsh nobleman, politician, knight, and courtier. He was a member of the Welsh gentry family that came to be known as the Herbert family through his son William Herbert, 1st Earl of Pembroke and is an ancestor of the current Earls of Pembroke.

Raglan manor, attained through marriage through heiress Elizabeth Bluet, was greatly expanded by William and his son, William Herbert, into the well-fortified Raglan Castle, one of the finest late medieval Welsh castles. William served King Henry V of England during his first French campaign and in numerous subsequent capacities and was knighted in 1426.

Full information available here:

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Sir William ap Thomas, The Blue Knight of Gwent's Timeline

Raglan, Monmouthshire, Wales (United Kingdom)
Raglan, Monmouthshire, UK
Itton, St. Arvans, Marches, Wales (United Kingdom)
Rhaglan, Usk, Monmouthshire, Wales (United Kingdom)
Ragland, Monmouthshire, England
Raglan Castle, Monmouthshire, Wales (United Kingdom)
Coldbrook, Abergavenny, Monmouthshire, Wales (United Kingdom)
Raglan, Sir Fynwy, Wales, United Kingdom