John, who sat in all four of the Parliaments summoned in the 1450s, was the eldest of the five sons of John Seymour I, whose inherited wealth had elevated him to the first rank of the gentry of Wiltshire. His parents married in July 1424, so even if he was their first child he cannot have been born before the spring of 1425. He perhaps attained his majority before his marriage to Elizabeth Coker which took place before 1 December 1447, the date that his father obtained a royal licence to settle on them and their male issue his moiety of the manor of Stapleford, which was held of the Crown in chief.
At the date this tax was levied Seymour’s first Parliament was in session at Westminster. Still in his mid twenties he had been returned by the Wiltshire borough of Hindon. Lordship of the borough pertained to William Waynflete, bishop of Winchester, whom his father was currently serving as constable of Farnham castle. John too entered Waynflete’s service. Thus, he was joined with the bishop in transactions concerning the manor of Stainswick in Berkshire, which had belonged to the late William Danvers*, when Danvers’s widow Joan conveyed it to Waynflete and his nominees in July 1453, as a preliminary to its donation to Magdalen College, Oxford.
Bishop Waynflete was made chancellor of England in October 1456, and a year later Seymour was appointed sheriff of his home county. Save for the commission to distribute tax allowances in 1453 (to which all the representatives of shires were named), this was his only recorded promotion to Crown office. His appointment on 7 Nov. 1457 fell on the same day that his father began his own seventh shrievalty, in his case in Herefordshire, where the Seymours held estates but had hitherto played no part in local affairs.
There is little information about Seymour’s whereabouts during the civil war years of 1459-61, save for his election, once again as a knight of the shire, to the Parliament at Coventry which was opened by Waynflete as chancellor on 20 Nov. 1459 and passed an Act of Attainder against the duke of York and his allies. Curiously, however, Seymour was not appointed to any of the commissions set up to array the country in defence of the Lancastrian government, and nothing is heard of him until after Edward IV had seized the throne. Even then the record relates to a private dispute rather than involvement in national politics. Seymour had quarrelled with the rector of Lydeard St. Lawrence regarding land and tithes in the parish. By an award made by Bishop Bekynton in his palace at Wells in August 1461, it was decided that Seymour should pay the rector 6s. 8d. for tithes, and the rector and his successors were to keep specified acres of arable land while allowing Seymour and his issue by his wife Elizabeth to have untroubled possession of the rest of the disputed property.
The MP’s widow married Richard Whitley†, a Lincoln’s Inn lawyer from Devon, but outlived him too. She had retained the Seymour moiety of Stapleford, which passed on her death in 1472 to her son John Seymour of Wolf Hall, by then aged 21.
