Sir Hugh de Courtenay, 2nd/10th Earl of Devon (12 July 1303 – 2 May 1377), 2nd Baron Courtenay, feudal baron of Okehampton and feudal baron of Plympton, played an important role in the Hundred Years War in the service of King Edward III. His chief seats were Tiverton Castle and Okehampton Castle in Devon. The ordinal number given to the early Courtenay Earls of Devon depends on whether the earldom is deemed a new creation by the letters patent granted 22 February 1334/5 or whether it is deemed a restitution of the old dignity of the de Redvers family. Authorities differ in their opinions, and thus alternative ordinal numbers exist, given here.
 Hugh de Courtenay was born on 12 July 1303, the second son of Hugh de Courtenay, 1st/9th Earl of Devon (1276–1340), by his wife Agnes de Saint John, a daughter of Sir John de Saint John of Basing, Hampshire. He succeeded to the earldom on the death of his father in 1340. His elder brother, John de Courtenay (c.1296-11 July 1349), Abbot of Tavistock, as a cleric was unmarried and although he succeeded his father as feudal baron of Okehampton, did not succeed to the earldom. 
 By his marriage to Margaret de Bohun, Countess of Devon in 1325, Courtenay acquired the manor of Powderham; it was later granted by Margaret de Bohun to one of her younger sons, Sir Philip Courtenay (died 1406), whose family has occupied it until the present day, and who were recognised in 1831 as having been de jure Earls of Devon from 1556.[citation needed]
 On 20 January 1327 Courtenay was made a knight banneret. In 1333 both he and his father were at the Battle of Halidon Hill. He was summoned to Parliament on 23 April 1337 by writ directed to Hugoni de Courteney juniori, by which he is held to have become Baron Courtenay during the lifetime of his father. In 1339 he and his father were with the forces which repulsed a French invasion of Cornwall, driving the French back to their ships. The 9th Earl died on 23 December 1340 at the age of 64. Courtenay succeeded to the earldom, and was granted livery of his lands on 11 January 1341.
 In 1342 the Earl was with King Edward III's expedition to Brittany. Richardson states that the Earl took part on 9 April 1347 in a tournament at Lichfield. However, in 1347 he was excused on grounds of infirmity from accompanying the King on an expedition beyond the seas, and about that time, was also excused from attending Parliament, suggesting the possibility that it was the Earl's eldest son and heir, Hugh Courtenay, who had fought at the Battle of Crecy on 26 August 1346, who took part in the tournament at Lichfield.
 In 1350 the King granted the Earl permission to travel for a year, and during that year he built the monastery of the White Friars in London. In 1352 he was appointed Joint Warden of Devon and Cornwall, and returned to Devon.[citation needed] In 1361, he and his wife were legatees in the will of her brother, Humphrey de Bohun, 6th Earl of Hereford, which greatly increased his wealth and land holdings.[citation needed]
 Courtenay made an important contribution to the result of the Battle of Poitiers[citation needed] in 1356. The Black Prince had sent the baggage train under Courtenay to the rear, which proved to be a wise manoeuvre as the long trail of wagons and carts blocked the narrow bridge and the escape route for the French. Courtenay played little part in the battle as a result of his defensive role.  Courtenay retired with a full pension from the king.[citation needed]  In 1373 he was appointed Chief Warden of the Royal Forests of Devon, the income of which in 1374 was assessed by Parliament at £1,500 per annum.[citation needed]  He was one of the least wealthy of the English earls, and was surpassed in wealth by his fellow noble warriors the Earl of Arundel, Earl of Suffolk  and Earl of Warwick. Nevertheless, he had a retinue of 40 knights, esquires and lawyers in Devon.[citation needed] He also held property by entail, including five manors in Somerset, two in Cornwall, two in Hampshire, one in Dorset and one in Buckinghamshire. He had stood as patron in the career of John Grandisson, Bishop of Exeter. He supported the taking-on[clarification needed] of debt to build churches in the diocese of Exeter.[citation needed]
 He died at Exeter on 2 May 1377 and was buried in Exeter Cathedral on the same day.[citation needed] His will was dated 28 January 13--.
 On 11 August 1325, in accordance with a marriage settlement dated 27 September 1314, Courtenay married Margaret de Bohun (b. 3 April 1311 - d. 16 December 1391), eldest surviving daughter of Humphrey de Bohun, 4th Earl of Hereford (by his wife Princess Elizabeth, a daughter of King Edward I), by whom he had eight sons and nine daughters: