top of page

Clyst Heath, 1455 (Conflict in Medieval Devon extract)

The battle at Clyst Heath was the culmination of nearly two decades of strife between Devon’s two most prominent families: the Courtenays and the Bonvilles. The Courtenay family held the Earldom of Devon since 1335, superseding the Redvers as the most powerful noble family in Devon. Courtenay holdings included vast tracts of land, castles, fortified manor houses and estates, as well as the lucrative stewardship to the Duchy of Cornwall. The Bonvilles began as minor nobility and retainers of the Courtenays; William Bonville was knighted by Thomas Courtenay’s grandfather, Edward Courtenay. However, in the early part of the 15th Century, William Bonville gained increasing prominence and royal favour which would eventually be the cause of great friction between the two noble families.

Thomas Courtenay’s father, Hugh, died in 1422 and it wasn’t until 1433 that the young Thomas came into his majority. Even then, he wasn’t able to take his seat at the traditional residence of the Earl of Devon in Tiverton because it was legally held by his mother, along with the majority of the Courtenay estates. Meanwhile, the period of over a decade when Thomas was in his minority had allowed William Bonville the opportunity to gain increasing prominence: he was appointed as the sheriff of Devon in 1423, Justice of the Peace for Devon in 1431, and in 1427 he married Thomas Courtenay’s aunt Elizabeth. Historian R.L Storey suggests that Bonville’s marriage to Elizabeth Courtenay may have been the main instigator of the troubles between the two families as it created a dispute over her property. Regardless, the real strife started in 1437 when Bonville became a member of the king’s council and gained the stewardship to the Duchy of Cornwall, denying the Courtenays a significant source of revenue.

Bonville’s gains had now started to impact Courtenay’s wealth and influence at court, and Thomas Courtenay wasn’t about to sit by and let a minor noble get the best of him. The matter came before the king’s council, which in fact made matters worse. Courtenay petitioned to have the stewardship of the Duchy of Cornwall returned to him. The council relented – only to then refuse Courtenay the rights of the post, leaving both Bonville and Courtenay to presume their right to the stewardship. The dispute became so bitter that the king’s council had to intervene and arbitrate.

Along with loss of land and title formerly associated with the Courtenay family, came loss of influential friends. Powerful families such as the Hungerfords noted the change in fortunes and gradually shifted allegiance toward the Bonville faction. Even Thomas’s cousin, Philip Courtenay, who held the fortified manor at Powderham in Devon, became closely allied with Bonville and ostracised from the Courtenay faction.

Violence broke out in 1439 when Thomas attacked Bonville holdings – the precise details are not known, but likely took the form of assaults against tenants and their property, affecting Bonville’s income and challenging his ability to protect his land and tenants. Royal intervention failed to settle the matter and minor outbreaks of violence continued. Again, the king’s council made matters worse by returning the stewardship of the Duchy of Cornwall to Courtenay in 1441, and then almost immediately transferring it to Bonville. Failing to resolve the dispute between the two men, the council’s solution was to send Bonville out of the country for what they probably hoped would be a cooling-off period. In 1442, Bonville was sent to support the Earl of Somerset in France. There he remained until 1446, leading an impressive retinue of 20 men-at-arms and 600 archers.

Courtenay used this time to strengthen his own position at home and was appointed High Steward of England in 1445. Courtenay served briefly in France – perhaps feeling secure in his titles and holdings in England – but before long both men were back in Devon, with Bonville being elevated in 1449 to the title of Lord Bonville of Chewton.

Tension remained between Bonville and Courtenay, but there was no further violence until 1451. Bonville had lent support to the Earl of Wiltshire in a dispute with Lord Cobham, both of whom held lands in Somerset. Cobham was in turn supported by Courtenay. The matter provided enough of an excuse for Courtenay to call his retainers and march on Taunton, where on 22nd September 1451, he occupied the town with a military force numbering several thousand.

The Cobham-Courtenay faction next marched against the Earl of Wiltshire who had gathered an armed force near Bath. The two sides arrayed their armies for battle, but Wiltshire withdrew, and combat was avoided. Courtenay then returned to Taunton and again lay siege to Bonville at Taunton Castle. The castle was encircled, earthworks dug, and siege engines constructed. In the meantime, Wiltshire, who was a royal favourite, had gone to the king and pleaded for assistance. A royal army was being mustered to relieve Bonville, but it wasn’t to be needed as Richard, Duke of York, arrived on the scene first at the head of a small army and forced the opposing nobles into an uneasy peace and compelled Courtenay to lift his siege. The intervention was only a temporary measure as, again, nothing was done to resolve the disputes.

The 1450’s were a period of increased political instability in Britain – much of it resulting from the mental illness suffered by King Henry VI from 1453 onwards. The seeds for what would become the Wars of the Roses were sewn in 1452 when the Duke of York pressed to be named as heir of the childless Henry VI. At this early stage, likely frustrated with his lack of support from the crown, Courtenay threw in his lot with York. When York was arrested at Dartford in 1452, Courtenay fell out of favour with the crown, allowing Bonville to eclipse him. Bonville succeeded in getting his stewardship to the Duchy of Cornwall confirmed for life, as well as becoming constable of Rougemont Castle in Exeter. For his support of York, Courtenay lost his possession of Lydford Castle and the Forest of Dartmoor (which by this time had been reduced from a Royal Forest to a Chase). It was a crushing defeat for the Courtenays who had lost almost everything.

In 1453, the king fell into a catatonic state, incapacitating him as monarch and leading to York being appointed as Lord Protector. York used this position to settle old scores and lend favour to his supporters. Given the opportunity for revenge, Courtenay raised a small force of armed men and led attacks on Bonville’s tenants – much the same as he had done in 1439. In April 1454, Courtenay tried to ambush Bonville outside Exeter. Again, royal intervention was required, enforcing peace on the nobles against the significant bond of 4,000 marks. It had little effect.

Henry VI recovered from an 18-month period of catatonia in early 1455, at which point Courtenay seems to have decided that he was getting nowhere by supporting York whose affiliations had brought him closer to Bonville. Courtenay switched allegiances again and threw in his lot with the King, joining him in battle against York at St. Albans in May 1455. Courtenay’s shift in allegiance was ill-timed: the battle was an overwhelming Yorkist victory, Henry VI was captured, and Courtenay wounded.


Thomas Courtenay, 13th Earl of Devon Born in 1414. His father, Hugh, died in 1422. As Thomas was the only living son, he became Earl of Devon at age 8 although it wouldn’t be until his age of majority that he would hold any real power himself. Also in 1422, Thomas was married to Margaret Beaufort, the daughter of John Beaufort, Earl of Somerset – they would have 8 children together. Thomas was knighted by the king in 1426. Courtenay inherited forty manors in Devon along with land and rents in Cornwall, Somerset, and Dorset.

Baron William Bonville, Knight of the Garter Born in Devon in 1392, Bonville had to fight for his titles and rights from an early on. By the time he had come of age, the estates he was due to inherit had been granted to others, including Edward, Duke of York. Bonville was forced to sue to gain estates held by other members of his family in several counties. By the late 1420’s he had succeeded in regaining most of his inheritance, with more to follow in the 1430’s, including Yelverton in Devon, Taunton in Somerset, and his birthplace at Shute. Bonville gained royal favour by fighting at Agincourt under Henry V’s brother, the Duke of Clarence, and serving in several later campaigns of the Hundred Years Wars. He led a retinue of 10 men-at-arms and 30 archers in Gloucester’s army in 1423/4 and was wealthy enough to loan money to Clarence and influential enough to be appointed as one of the executors of Clarence’s will.

William Bonville Coat of Arms

Thomas Courtenay Coat of Arms

The siege of Powderham and the Battle of Clyst Heath

The political turmoil of the Wars of the Roses allowed opportunities for nobles on opposing sides to settle scores. In October 1455, Courtenay’s sons, Thomas and John, slew Nicholas Radford, a lawyer and MP who was a close associate of Bonville. The Courtenays’ launched fresh attacks on Bonville’s holdings and those of his allies, including occupying Exeter with a military force of up to 1,000 men and then laying siege to Philip Courtenay’s stronghold at Powderham Castle near Exeter. Bonville marched from his estate at Shute in Somerset, raiding Thomas Courtenay’s estate at Colcombe on 3rd November before eventually moving to attempt the relief of Powderham. Arriving at the Exe on 19th November, Bonville found Courtenay waiting for him at the head of about half of his force. A brief skirmish ensued in which Bonville’s men were beaten back.

Despite Courtenay’s minor victory, he soon abandoned his siege and moved to north to Exeter, fearing that Bonville would take advantage of his absence to retake the city. He was right to anticipate Bonville’s move: the two forces met again on 15th December at Clyst Heath, just east of Exeter and several miles north of Powderham.

Billmen marching behind The Earl of Devon’s banner

There is little detail of the engagement. Both sides fielded at least several hundred men, with Courtenay possibly commanding as many as a thousand. However, the actual engagement doesn’t appear to have been deemed noteworthy by most chroniclers of the time – it is only recorded that Courtenay won the day. The number of casualties has been variously estimated between dozens and hundreds – the lack of interest in the battle indicates that the number of dead was likely on the lower end of estimates and that the fight was a brief affair. Regardless, Bonville’s force fled the field in disarray leaving the Courtenays’ free to push further east and raid Bonville’s estate at Shute.


York had Courtenay sent to the Tower of London for his belligerence – the stay was brief. Henry had Courtenay freed in February 1456. Although Courtenay had been the aggressor in the affair, Bonville was briefly incarcerated in Fleet prison, presumably due to his links with York.

In 1459, Bonville swore his allegiance to Henry in front of Parliament. However, when hostilities resumed between the crown and York in 1460, Bonville supported the Yorkist cause and fought at the battles of Northampton and Wakefield. Bonville was captured at the second battle of St. Albans and executed for treason. He did however outlive Thomas Courtenay, who died on 3rd February 1458. The Courtenay family remained on the Lancastrian side throughout the Wars of the Roses and all of Thomas’s sons lost their lives in the fighting, eliminating the main male line of Courtenay household. After years of bickering, what started as a local dispute over land, title, and royal patronage had only been resolved by the deaths of all the leading participants. Once the fighting of the Wars of the Roses was over, the earldom was recreated by Henry VII and granted to Edward Courtenay, whose grandfather was the younger brother of the 11th Earl.

Read about other battles, sieges, and raids in medieval Devon in this new book available to preorder now.


Recent Posts
Search By Tags
bottom of page