Robert was born between 1408 and 1417 as a younger son of Richard, earl of Oxford. He was thus about eight years old or younger when his father died on 15 Feb. 1417 and his brother John, himself aged less than nine, succeeded to the earldom. Custody of the young earl and his lands was first granted to Thomas Beaufort, duke of Exeter, and after his death in December 1426 to the King’s uncle, the duke of Bedford. Although no specific provision was made, it is probable that the heir’s younger brother, who might yet have to take his place, should the earl die under age and childless, was brought up with him.
In July 1429, the earl of Oxford had livery of his lands. Robert had to wait rather longer to come of age, and his fate during much of the 1430s is obscure, but it is clear that his upbringing in the households of two of the greatest magnates and military commanders of their day predestined him for a career on the battlefields of France. His early experience of the wars was evidently not a happy one. The circumstances of his first journey to France are uncertain, but by December 1435 he found himself a prisoner in French captivity, and two men of Blois had to be dispatched to pay his ransom.
The campaign was a successful one and in the course of 1440 the fortress of La Roquette and the town of Bazas were recaptured from the French.
At some point before then de Vere had established ties with the King’s uncle, Humphrey, duke of Gloucester, although the nature of these ties and the way in which they came about, are uncertain. Perhaps, not long after regaining his freedom from French captivity, he had joined his elder brother in Gloucester’s expedition for the relief of Calais in 1436. Certainly, he was a member of the ill-fated duke’s retinue at Bury St. Edmunds in February 1447, and although he was not among the first wave of Gloucester’s servants taken into custody on the same day as their master, he was arrested three days later, on 21 Feb., while at dinner.
It seems that de Vere’s links with Gloucester were not held against him, and before long he was once more entrusted with independent command. Nevertheless, his actions proved controversial. On 24 Mar. 1449 the Breton fortress of Fougères was taken for the English by an assaulting force led by the Arragonese knight François de Surienne. In response to the efforts of Duke Francis I of Brittany to recapture it, in September Sir Robert was indentured to take a much needed relief force of 100 men-at-arms and 300 archers, but instead of leading this body of men directly to the siege, he advanced only as far as Caen and stayed there, causing Surienne to complain bitterly of being abandoned.
The loss of Normandy left the life that de Vere had built for himself in ruins. It may have been all too apparent to him that English Gascony also was likely to fall before long, or he may have been disinclined to settle for less than the office of seneschal that he had pursued in the 1440s. Whatever the case, he did not return to France. As his elder brother had by now fathered several sons, his chances of succeeding to the earldom were diminished, and he needed to find an advantageous marriage for himself. Such a match presented itself in the person of the widowed Joan Carew, one of the two daughters of Sir Hugh Courtenay of Haccombe by his third wife, Philippa Archdeacon. At Sir Hugh’s death in 1425 his own lands had descended to his elder son by his fourth and final marriage, but Philippa’s lands had been divided between their daughters, Joan and Eleanor. As the latter died shortly afterwards, Joan brought to her successive husbands her mother’s manors of Haccombe, Ringmore, Combhall (in Drewsteignton), Comb Netherton (in Combe in Teignhead), Shobrooke and South Milton, and lands in Herefordshire, Shropshire, and Essex.
Crucially, de Vere’s marriage also provided him with a tie to another family of comital rank, the Courtenay earls of Devon, a connexion which would do much to shape the final decade of his career. In the immediate aftermath of the fall of Normandy, Richard, duke of York, had begun to position himself as a figurehead for those discontented with the conduct of the war by Henry VI’s government, now headed by none other than the duke of Somerset whom many blamed for the loss of Normandy. Among York’s earliest partisans among the lords was Thomas Courtenay, earl of Devon, who continued to be disgruntled at having been denied the stewardship of the duchy of Cornwall in favour of his local rival, the recently ennobled Lord Bonville, a gripe with which de Vere, who had been forced to surrender the sénéchaussée of Gascony ostensibly in Bonville’s favour, could sympathise. It nevertheless seems that he took no part in the earl’s early campaign of score-settling which saw him lay siege to Bonville in Taunton castle in September 1451, even though his wife’s half-brother, Sir Hugh Courtenay*, was among the prominent leaders of the earl’s host. Nor did he, perhaps mindful of his experience in 1447, allow himself to be drawn into the more wide-ranging campaign against the King’s ministers, which saw both York and Devon arrested at Dartford early in the following year. Indeed, it is possible that even by this date he had entered the service of Henry Holand, duke of Exeter, under whose father he had seen service in France. Henry had succeeded to the dukedom on his father’s death in 1447, and had been granted livery of his estates in the summer of 1450. These included holdings in the south-west focused on the Devon manor of Dartington, and de Vere went on to serve as receiver of these holdings, as well as assuming the more important office of the duke’s chamberlain.
In the meantime, however, de Vere had been occupied closer to home. By the end of 1453 the earl of Devon had regained his liberty, and set about settling his score with Bonville with renewed vigour. In the spring and early summer of 1454 the earl’s retainers rampaged through the Devon countryside. They twice occupied Exeter, and on the second occasion directly attacked the city’s mayor. It fell to Sir Robert to intervene and restore order, a service for which he was subsequently rewarded by the grateful citizens. Yet, in the absence of any official authority for doing so, he suffered the indignity of being treated like another law-breaker and was summoned alongside his brother-in-law, Sir Hugh Courtenay, two of the earl of Devon’s sons and Roger Champernowne* of Bere Ferrers, to appear in Chancery (now presided over by the earl of Salisbury) to answer for certain riots, presumably the events at Exeter.
The Courtenays’ activities were just one facet of the escalating feuding between rival lords that had been exacerbated by the King’s mental incapacity in the second half of 1453. In the spring of 1454 de Vere himself had clashed several times with the unruly Cornish branch of the Beauchamp family, apparently over property rights in Pengelly.
In the longer term, de Vere’s association with York may have done him no favours. In September 1456 he was omitted from the Devon commission of the peace, while Earl Thomas was restored to it, and although he served a further stint on the bench in 1457-8 other appointments came his way only occasionally. His public career became as erratic as the behaviour of his master, the duke of Exeter, with whom in some respects he was well matched. In his capacity as Exeter’s chamberlain, de Vere, who was said to have ‘all authority and power with the duke’, sold the marriage of the duke’s ward Thomas Deryng to William Durneford, the boy’s next of kin, for £20 and received payment in person, promising ‘by his knighthood’ to return the bond guaranteeing the transaction, or to issue a quittance. This he failed to do, forcing Durneford to make the payment a second time to avoid outlawry, as the hapless landowner complained to the chancellor.
De Vere was granted the freedom of the city of Exeter in January 1459,
In the aftermath of Sir Robert’s death, it was his widow, Joan, who fell victim to repeated reprisals by the partisans of the new dynasty, such as Thomas Gille II*.