[5] John Twynyho's sister-in-law [6] Ankaret Hawkeston, the wife of his elder brother William Twynyho of Keyford, had been a servant of Isabel Neville, Duchess of Clarence (died 1476), a daughter and co-heiress of Richard Neville, 16th Earl of Warwick (1428–1471) The Kingmaker, whose death in childbirth had been blamed by her husband George Plantagenet, 1st Duke of Clarence (executed 1478), on a poisoning by Ankaret.
Clarence was determined to have Ankaret executed, against the wishes of the Queen, who believed her to be an elderly and harmless widow blamed unjustly.
[7] Twynyho was in partnership with the wool merchant John Tame (died 1500), the builder of Fairford Church in Gloucestershire and a favourite of King Henry VII, and the pair had expanded their sheep, wool and cloth business in a bold fashion by acquiring large amounts of sheep rearing land, including Fairford in 1479.
[9] In about 1464 Cecily, Duchess of York had been granted by her son the king the advowson of the Hospital of St. John the Baptist, Lechlade, an Augustinian Priory founded in 1246 by Isabella de Mortimer.
In 1472 she founded a chantry for three chaplains to celebrate divine service daily in the Chapel of the Virgin in the parish church of Lechlade, and John Twynyho's licence was granted by her at the same time.
[10] In 1484 he was chief steward of the lordship of Thornbury in Gloucestershire,[11] former seat of Henry Stafford, 2nd Duke of Buckingham (1454–1483), executed for treason in 1483, when the manor was forfeited to the crown.
The north and south chapels in that church are likely to have been paid for by the Duchess of York and John Twynyho to house the chantries founded in 1472.