

トーマス・コートニー、第6代/第14代デヴォン伯(1432年 - 1461年4月3日)は、第5代/第13代デヴォン伯トーマス・ド・コートニーと、その妻マーガレット・ボーフォート(初代サマセット伯ジョン・ボーフォートと、第2代ケント伯トーマス・ホランドの娘マーガレット・ホランドの娘)の長男であった。母を通じて、彼はエドワード3世の玄孫にあたる。初期のコートニー家のデヴォン伯に与えられた序数は、伯爵位が1334/5年2月22日に与えられた特許状によって新たに創設されたものと見なされるか、それともド・レドヴァース家の古い地位の回復と見なされるかによって異なる。権威者たちの意見は分かれており[ 1 ]、そのため、ここでは別の序数が示されている。
コートニーは1432年に、第13代デヴォン伯トーマス・コートニーとマーガレット・ボーフォートの長男で相続人として生まれた。彼には2人の兄弟と5人の姉妹がいた。[ 2 ]
Thomas Courtenay was 26 years old when his father died on 3 February 1458.[4] The Courtenay family were among the greatest magnates of the south-west, especially in Devon, where they had their greatest concentration of estates and dominated a tightly-knit affinity among the local gentry.[5] In the mid-fifteenth century their local supremacy had been challenged by William, Lord Bonville, leading to a violent feud which culminated in Bonville's defeat by Thomas's father at Clyst Heath in 1455. That Earl, frequently in trouble with the law for his violent behaviour, had been among the closest allies of the disaffected Richard of York in the early 1450s, but a wedge was driven between York and the Courtenays when Bonville became a client of the leading Yorkist magnate Richard Neville, Earl of Warwick.
When the first major phase of the Wars of the Roses broke out in 1459, Earl Thomas remained loyal to Henry VI. After the Yorkists seized power and captured King Henry in 1460, he joined other south-western aristocrats including Henry Beaufort, Duke of Somerset in raising a Lancastrian army, which went to join the forces being gathered by the queen, Margaret of Anjou, in northern England. The Bonville family, fighting on the Yorkist side, were wiped out during the ensuing fighting, but the Lancastrians were decisively defeated in the Battle of Towton on 29 March 1461. Courtenay was captured in the battle, and was beheaded at York on 3 April.[6] He was attainted by Parliament in November of that year, depriving his heirs of the earldom of Devon, the barony of Courtenay and his estates. Courtenay's younger brother, Henry, had been granted several manors by King Edward IV on 27 July 1461, including Topsham, and these manors were also forfeited by his elder brother's attainder. Henry himself was beheaded at Salisbury on 17 January 1469.[7]
Courtenay married, at Coventry, Warwickshire, shortly after 9 September 1456, Mary of Anjou, illegitimate daughter of Charles, Count of Maine. There were no issue of the marriage. She is thought to have been the 'Countess of Devonshire' who was captured with Margaret of Anjou after the Battle of Tewkesbury on 4 May 1471.[7]