Thomas de Courtenay, 5th/13th Earl of Devon (3 May 1414 – 3 February 1458) was a nobleman from South West England. His seat was at Colcombe Castle near Colyton, and later at the principal historic family seat of Tiverton Castle, after his mother's death. The Courtenay family had historically been an important one in the region, and the dominant force in the counties of Devon and Cornwall. However, the rise in power and influence of several gentry families and other political players, in the years leading up to Thomas' accession to the earldom, threatened the traditional dominance of the earls of Devon in the area. Much of his life was spent in armed territorial struggle against his near-neighbour, Sir William Bonville of Shute, at a time when central control over the provinces was weak. This feud forms part of the breakdown in law and order in England that led to the Wars of the Roses.

Courtenay was for a time engaged in overseas service during the Hundred Years' War. Increasingly, however, his efforts became directed towards strengthening his position at home. He had been married off as an infant to Margaret Beaufort, placing Courtenay close to the English king's Beaufort kinsmen. Due to this connection, Courtenay started his career as an adherent to the English court's Beaufort party. Upon their demise in the late 1440s, he abandoned it in favour of Richard Plantagenet, 3rd Duke of York. When York sought the support of Courtenay's arch-enemy Bonville, Courtenay fell out of favour with him. When the Wars of the Roses broke out, he was in the party of the queen, Margaret of Anjou, and was one of the Lancastrian commanders at the First Battle of St Albans, where he was wounded.

Courtenay was said to have promoted a reconciliation between the Lancastrian and Yorkist parties, but he died suddenly in 1458. The Wars of the Roses later led to the deaths and executions of all three of Courtenay's sons, Thomas, Henry and John, and to the eventual attainder of his titles and forfeiture of his lands. The earldom was, however, revived in 1485 for his distant cousin, Sir Edward Courtenay, third in descent from his great-uncle.

Youth Courtenay was born on 3 May 1414, the only surviving son of Hugh Courtenay, 4th/12th Earl of Devon (1389 – 16 June 1422) and Anne Talbot (c. 1393 – 1441), sister of the renowned warrior John Talbot, 1st Earl of Shrewsbury. He succeeded as Earl of Devon in 1422, at the age of eight. He may at some time before have become a ward of the all-powerful Thomas Beaufort, Duke of Exeter.

According to Cokayne, Courtenay was knighted on 19 May 1426 by King Henry VI of England, and on 16 December 1431, Courtenay was among an entourage of 300 who attended King Henry VI's second coronation at Notre Dame in Paris.

Majority It appears that no inquisition of proof of age, customary for a tenant in chief, was taken for his father. Based on his family's history and standing and on his own position as the leading landowner of the county, probably expected to take his place as the leader of Devon society. However, his mother's longevity meant that her dower portion, including Tiverton Castle, and the other Courtenay estates which had been alienated under his father's will were not in his hands and the young Courtenay was forced to live at Colcombe Castle, near Colyton, very close to his enemy William Bonville, 1st Baron Bonville, at Shute. His income of £1,500 p.a. was lower than that of most nobles of comparable rank.

Career Struggle with Bonville

The new earl found the political situation in Devonshire increasingly stacked against his own interests as a coalition of the greater gentry, led by William Bonville, 1st Baron Bonville, and the earl's cousin, Sir Philip Courtenay of Powderham, threatened the Courtenays' traditional dominance of the county. The relationship was complicated by Bonville's second marriage in 1430 to Elizabeth Courtenay (d. 1471), Courtenay's aunt. Despite links via his wife, Margaret Beaufort, to the ascendant "court party" led by Cardinal Beaufort and John Beaufort, 1st earl of Somerset and Marquess of Dorset, and by Margaret Holland, daughter of the Earl of Kent, Courtenay failed to rectify his situation and instead resorted to violence, beginning in 1439. With the decline of Beaufort power, Courtenay became increasingly associated with Richard Plantagenet, 3rd Duke of York. Courtenay had been attacking Bonville's estates in the summer of 1439 and the king despatched a Privy Councillor, Sir John Stourton, 1st Baron Stourton, to extract a promise of good behaviour from Courtenay, who was thereafter reluctant to attend the court in London.The pirate-soldier, Sir Hugh Courtenay, a cousin, looted merchant vessels along the coast, and led brigands with Thomas Carminow, after a long dispute with the Earl. In 1441, Courtenay was appointed as Steward of the Duchy of Cornwall, a nearly identical post to Royal Steward for Cornwall which had been granted to Sir William Bonville in 1437, for life. A week later in May 1441, the warrant was retracted. Disputes arose between the two which contemporary records portray as reaching the status of a private war. Two men wearing Courtenay livery attacked Sir Philip Chetwynd, a friend of Bonville, on the road to London, apparent evidence that the council's arbitration of November 1440 had failed.The "Arbitration" was published on 1 April 1442. Courtenay and Bonville were summoned before the King in December 1441, and were publicly reconciled. Tensions remained, however, and this may have been a factor in the crown's requests to both Courtenay, who initially refused, and Bonville to serve in France, Bonville as seneschal of Gascony from 1442 to 1446 and Courtenay at Pont-l'Évêque in Normandy in 1446. This is one of the few times that Courtenay served abroad, for he had refused in March 1443, seemingly preferring to spend his time bolstering his position in Devon or at court. While Bonville was abroad, the King released Devon from his debts, including the recognisance for good behaviour, probably remitted by the influence of father-in-law, John Beaufort, Earl of Somerset.

Royal appointments Commissions His advantageous marriage to Margaret Beaufort brought him links to the "court party", and Courtenay began to be selected by the king to serve on Westcountry commissions and was granted an annuity of £100 for his services.

Other 1445 marked a fleeting high point in Courtenay's fortunes, with his appointment as High Steward of England at Queen Margaret's coronation on 25 May. Only the year before, March 1444, Bonville had identified himself with Suffolk, at Margaret's betrothal in Rouen.

Abandonment of Beauforts The deaths of his brother-in-law John Beaufort, 1st Duke of Somerset, in 1444, and of the leader of the party Cardinal Beaufort, second son of John of Gaunt, in 1447, removed Beaufort leadership of the 'court' party, leaving William de la Pole, 1st Duke of Suffolk, as the most influential figure in national politics. and for differing views on the relationship between Suffolk and Henry VI. While there is no evidence of direct antagonism between Courtenay and the Duke of Suffolk, the latter appeared to favour the Bonvilles. Sir William Bonville enjoyed links with Suffolk and married his daughter to William Tailboys, one of the Duke's closest associates. Perhaps the most dramatic illustration of this favour was Bonville's elevation to the peerage, presumably at the direction of Suffolk, as Baron Bonville of Chewton Mendip in 1449.

Switch to Yorkist party This promotion of his enemy Bonville may have prompted Devon to oppose the 'Court party' and to serve with his friend Richard Plantagenet, 3rd Duke of York during Jack Cade's Rebellion. Courtenay switched allegiance to York, who with the Duke of Norfolk took control briefly of London. He remained loyal to York during the Parliament of November 1450, when they invoked the support of the Commons to raise taxation. Having rescued the Duke of Somerset from an angry London mob, York himself had to flee, taking refuge on the Earl of Devon's barge rowing down the Thames. It is hardly surprising that Devon began to become associated with York, who had assumed the leadership of the "opposition" party. The parlous state of national politics (whether the king was a vindictive factionalist or an inane non-entity is largely irrelevant in this context) combined with what seems like a reckless and violent element in Courtenay's own character, led to a further campaign of violence against Bonville and the Suffolk-aligned James Butler, 5th Earl of Ormond and Earl of Wiltshire. Courtenay and his troops attempted to capture Butler near Bath in Wiltshire before returning to besiege Bonville in Taunton Castle. The arrival of York (whether to suppress or aid the disturbances is uncertain) caused the two sides to make peace which, unsurprisingly, had no real meaning. York then embarked on his abortive attempt to take control of the royal government by force, his only allies being Courtenay and his sometime-associate, Edward Brooke, 6th Baron Cobham.

In the West Country, Courtenay hounded Bonville without mercy, and pursued him to Taunton Castle and laid siege to it. York arrived to lift the siege, and imprisoned Bonville, who was nevertheless quickly released. This exploit ended with the disgrace of all three 'Yorkists' and their submission to royal mercy in March. The King had issued an arrest warrant on 24 September 1451, drafted by Somerset, to be enforced by Butler and Bonville. The Yorkist rebellions prompted royal commissions for Buckingham and Bonville on 14 February 1452. A direct summons without delay was ordered by Royal Proclamation on 17 February to bring Courtenay and Lord Cobham to London.Lord Cobham had been dispossessed by the Earl of Wiltshire, a creation of Henry VI.ibid, 98

Treason charge Courtenay was charged with treason and briefly imprisoned in Wallingford Castle, before appearing on trial before the House of Lords. His disgrace and political isolation allowed his Devonshire rivals to consolidate their positions, further undermining his decreased standing in the county. Bonville acquired all royal commissions in the south-west.

Resurgence of York King Henry VI's madness and York's appointment as Protector in 1453/4 resulted in a partial rally in Courtenay's fortunes, including his re-appointment to commissions of the peace in the south-western counties, the key barometer of the local balance of power. He was a member of the Royal Council until April 1454. Courtenay was bound over to keep the peace with a fine of 1,000 marks, but ignored its restrictions. Threatened by the council on 3 June, he was forced on 24 July to make a new bond.

Abandonment by York This was, however, the end of Courtenay's links with York, whose increasingly tight links with the Neville earls of Salisbury and Warwick led to an alignment with Bonville away from Courtenay. This culminated in the marriage of William Bonville, 6th Baron Harington, Bonville's grandson, to Salisbury's daughter, Katherine. Courtenay did not endear himself to Somerset either, as he and his sons repeatedly disrupted the sessions of the commissioners of the peace in Exeter during 1454/5, which did not assist Protector Somerset in promoting his role as the guardian of law and order. Courtenay was present at the First Battle of St Albans, and was wounded. York, however, still considered him at least neutral as the duke's letters addressed to the King on the eve of battle were delivered to the king via the apparently still trusted hands of Courtenay.

Final assault on Bonville