After Thomas's father became ill in 1411, his older brother Henry became head of the royal council. Conflicts arose between the young Henry and his father when the prince gathered a group of supporters favouring his policy of declaring war on France. The prince was removed from the council by his father after he had defied the king's wishes by persuading it to declare war. Thomas was given his brother's seat, and fell in line with his father's peace policy. Though he remained Lord Lieutenant of Ireland until 1413, he did not return to
Ireland after 1409. He seems to have been a conscientious Governor there, but was hampered in his efforts to keep the peace by the chronic shortage of money in Ireland.
Military career , from
Les Vigiles de Charles VII During the wars of his elder brother
Henry V in France, Clarence fought in both the
Siege of Caen and the
Siege of Rouen (29 July 1418 – 19 January 1419), where he commanded the besieging force. After Henry had negotiated the
Treaty of Troyes, in which he became heir to the French throne, the king returned to England with his new wife Catherine. The Dauphin, the disinherited former heir, refused to accept the situation and organised continuing resistance, aided by a Scottish army led by
John Stewart, Earl of Buchan. Following the king's instructions, Clarence led 4,000 men in raids through Anjou and Maine. This
chevauchée met with little resistance, and by Good Friday, 21 March 1421, the English army had made camp near the little town of
Vieil-Baugé. The Franco-Scots army of about 5,000 also arrived in the Vieil-Baugé area to block the English army's progress; it was commanded by the Earl of Buchan and the Marshal of France, the
Sieur de Lafayette; however, the English forces were dispersed, and, significantly, many of the English archers had ridden off in search of plunder or forage. On Easter Saturday, one of these foraging groups captured a Scots
man-at-arms whom they brought before the Duke of Clarence. Clarence was keen to engage the enemy; however, he had a problem: the following day was Easter Sunday, one of the holiest days in the Christian calendar, when a battle would be unthinkable. A two-day delay was also deemed as out of the question. According to the chronicles of
Walter Bower, both commanders agreed a brief truce to celebrate Easter, but then joined battle that day. Perhaps underestimating the size of the Franco-Scottish army, Clarence decided to launch a surprise cavalry-led attack rather than use his archers against the enemy. With only about 1,500 men-at-arms available, and virtually no archers, he charged the Franco-Scottish lines. The shock temporarily disordered the Franco-Scots, but soon Clarence and his knights were overwhelmed. Clarence was unhorsed by a Scottish knight, Sir
John Carmichael of Douglasdale, and finished off on the ground by Sir
Alexander Buchanan, probably with a mace, "his jewelled and crowned helmet wrenched from his head as a prize". ==Burial==