Sir Thomas DE CLARE, Lord Of Inchiquin And Youghal 
- Born: Abt 1245, Tonbridge, Kent, England
- Marriage: Lady Juliana FITZ GERALD, Of Thomond  in Feb 1275 in , , Ireland
- Died: 29 Aug 1287, , Clare, Ireland about age 42 2
Sources, Comments and Notes:
"Thomas de Clare, Lord of Inchiquin and Youghal (c. 1245 \endash 29 August 1287) was a Hiberno-Norman peer and soldier. He was the second son of Richard de Clare, 6th Earl of Gloucester and his wife Maud de Lacy. On 26 January 1276 he was granted the lordship of Thomond by Edward I of England; he spent the next eight years attempting to conquer it from the O'Brien dynasty, kings of Thomond.
Thomas was born in about 1245 in Tonbridge, Kent, England, the second eldest son of Richard de Clare and Maud de Lacy. Thomas was a close friend and intimate advisor of Prince Edward of England, who would in 1272 accede to the throne as King Edward I. Together they went on Crusade. He held many important posts such as the Office of the Governor of Clochester Castle (1266), Governor of The City of London (1273). He was made Commander of the English forces in Munster, Ireland and created Lord of Inchiquin and Youghal. On 26 January 1276, he was granted the entire lordship of Thomond by King Edward.
That same year, he jointly commanded a Norman army along with Sir Geoffrey de Geneville, Justiciar of Ireland against the Irish clans of County Wicklow. They were joined by a contingent of men from Connacht led by his father-in-law Maurice FitzGerald, 3rd Lord of Offaly. Thomas and Justiciar de Geneville's forces attacked the Irish at Glenmalure, but they were soundly defeated and suffered severe losses.
Civil war raged in Thomond between the rival factions of the O'Brien dynasty. In 1276, Brian Ruad, the deposed King of Thomond appealed to Thomas for support to help him regain his kingdom from his great-nephew Toirrdelbach MacTaidg O' Brien, who had usurped the throne. In return for his aid, Brian Ruad promised that Thomas would be allowed to colonise all the land between Athsollus in Quin and Limerick. Together, Thomas and Brian Ruad expelled Toirrdelbach MacTaidg O'Brien and recaptured Clonroad which the latter had taken from Brian Ruad. O'Brien escaped to Galway where he elicited the help of his cousin William de Burgh, and in 1277 together with the assistance from clans, MacNamara and O'Dea they defeated the combined forces of Thomas and Brian Ruad. The latter fled to Bunratty Castle, but Thomas had his former ally hanged and drawn for treason. The civil war continued for the next seven years, with Thomas supporting Brian Ruad's son Donnchad against Toirrdelbach; however, following the drowning death of Donnchad in 1284, Toirrdelbach emerged the victor. Thereafter until his death in 1306, Toirrdelbach MacTaidg O'Brien ruled as undisputed King of Thomond and Thomas had no choice but to accommodate him. O'Brien rented part of Bunratty Manor at £121 per annum.
In 1280, Thomas embarked on a castle-building project at Quin, but was disrupted in his efforts by the O'Briens and MacNamaras.
Marriage and children
In February 1275, he married Juliana FitzGerald, the 12-year old daughter of Maurice FitzGerald, 3rd Lord of Offaly and Maud de Prendergast. Thomas and his wife made their principal residence at Bunratty Castle, which he had constructed in stone, replacing the earlier wooden structure. Together they had four children:
Maud de Clare (c. 1276\endash 1326/27), married firstly, Robert de Clifford, 1st Baron de Clifford, by whom she had issue; and secondly Robert de Welle
Gilbert de Clare, Lord of Thomond, (3 February 1281\endash 1308)
Richard de Clare, Steward of Forest of Essex, 1st Lord Clare, Lord of Thomond (after 1281 \endash 10 May 1318), married a woman by the name of Joan, by whom he had one son, Thomas. He was killed at the Battle of Dysert O'Dea.
Margaret de Clare (c. 1 April 1287 \endash 22 October 1333/3 January 1334), married firstly, Gilbert de Umfraville; and secondly Bartholomew de Badlesmere, 1st Baron Badlesmere, by whom she had issue.
Thomas was killed in battle on 29 August 1287 leaving behind four children, the youngest, Margaret being not quite five months old. He was succeeded as Lord of Thomond by his eldest son, Gilbert who was six years old. His widow Juliana, aged 24 years, would go on to marry two more times."
"... La première mention retenue par les Annales de l'activité de William Liath de Burgh se rapporte à l'année 1277. Il participe alors avec son cousin Richard Og de Burgh Comte d'Ulster à la guerre civile qui oppose Brian Ruadh O'Brien roi de Thomond (1268-1277) à son neveu Thoirdhelbach mac Tagd Cael Uisce O'Brien futur roi de Thomond (1276/1284-1306).Cette rivalité était accentuée par l'antagonisme de la Famille de Bourg avec la famille de Clare nouvellement implantée dans l'ouest de l'Irlande depuis qu'elle avait été investie en 1276 par le roi Édouard Ier d'Angleterre de l'ensemble du Thomond sous le nom de Comté de Clare.
Brian Ruadh O'Brien battu par son rival Thoirdhelbach mac Tagd Cael Uisce O'Brien à la bataille de Magh-Gresain est ignominieusement mis à mort par son allié Richard de Clare en 1277.Ce crime unit les O'Brien et les De Burgh contre le meurtrier. Il se soldera par meurtre de Thomas de Clare par Thoirdhelbach O'Brien en 1287 et l'expulsion postérieure des de Clare du Thomond. ..."
Thomas married Lady Juliana FITZ GERALD, Of Thomond  [MRIN: 1146], daughter of Lord Maurice II FITZ GERALD, Dit "Maurice Mael (Bald)", 3Rd Lord Of Offaly  and Maud DE PRENDERGAST, Lady Of Offaly , in Feb 1275 in , , Ireland. (Lady Juliana FITZ GERALD, Of Thomond  was born about 1263 in , , Ireland and died on 24 Sep 1300 in , , Ireland.)