The origins of the Polmorva family are obscure, but the MP is likely to have been related to the namesake who sat in Parliament for three different Cornish boroughs in the 1330s.
On All Saints Day 1391 Polmorva was attending mass at his parish church, when unbeknown to him a group of servants of Thomas Peverell† forced their way into his house and abducted his wife. Elizabeth was taken to Peverell’s house at Park and held there for five days until Polmorva agreed to pay £40 for her release. As a result of her ordeal, she lost her mind, and John, aware that Peverell’s status as a j.p. rendered a complaint before the county bench impractical, sued for redress in Chancery.
In the interim, Polmorva had fallen victim to an armed trespass by Richard Allet†, which may have arisen from the latter’s quarrel with his friend Arthur Hamely. On 3 Oct. 1402 Allet entered Polmorva’s house and carried off armour, silver vessels and other goods of a total value of £100. It took some years for the litigation which followed to come to a head: in the summer of 1407 Polmorva procured a writ of exigi facias in an attempt to have his opponent outlawed. As at the time he was himself serving as sheriff of Cornwall, he was ideally placed to ensure the smooth progression of this process, and even when Allet in turn procured a writ of supersedeas to prevent his outlawry from being pronounced, Polmorva’s dismissal from the shrievalty four days earlier allowed him to refuse to receive this latter document and halt the outlawry proceedings. In early 1408 Allet finally appeared in the court of King’s bench and formally surrendered to the Marshalsea before securing his immediate release by pleading a writ of error.
Early in the following year, Polmorva contracted to serve in the retinue of the captain of Oye in Picardy, the London mercer John Lardener. It is not clear whether he actually had any intention of sailing for France, for the protection he had been granted for this expedition on 18 Mar. was revoked five weeks later, as he delayed at Westminster, perhaps in connexion with an assize of novel disseisin brought against him and a number of associates by one John Tallan.
In 1418 Polmorva once more sought to fulfill his old ambition to fight in France and in January he joined the retinue of Thomas Beaufort, duke of Exeter. Beaufort set out for Normandy in May, and this time John appears to have also gone, for he disappears from the English records for the remainder of Henry V’s reign. If he stayed with Beaufort throughout these years, he may have participated in the successful Norman campaign right up to the relief of Cosne in August 1422, only then, like Beaufort, returning to England with the dead King.
Before embarking for France, Polmorva had married the widow of the lawyer Roger Trewythenick, with whom he had long been acquainted. In the reign of Richard II Trewythenick had been one of the busiest parliamentarians in the south-west, but it seems unlikely that his example provided any particular inspiration for Polmorva, who secured election for the borough of Liskeard when Henry VI’s first Parliament was summoned in October 1422. Although his connexion with the infant King’s guardian may have recommended him to the burgesses, it is probable that he ultimately owed his return for the duchy of Cornwall borough to the influence of the duchy steward, Sir John Arundell. In any case, Polmorva attended the shire elections at Launceston and attested the indenture which recorded the names of both shire and borough Members. It is uncertain whether he ever took his seat. While in France, he had contracted an illness of some sort – it is tempting to speculate whether it was the same that claimed the life of Henry V. Whatever the truth of the matter, by early November 1423 he was dead. He was survived by his second wife, Joan, and his putative daughter, Alice, who had married the influential Nicholas Carminowe. The latter lost no time in claiming his wife’s inheritance, much to the distress of the widow who complained bitterly that her dead husband’s son-in-law, ‘le plus graunde extortioner, oppressour et maintainour de tout le paijs’, had entered her dower lands, seized charters and muniments, driven away her livestock and carried off her household goods.
