John came from a well-established Essex family, and his uncle Sir Thomas Tyrell, who served as steward of the estates of Edward III’s daughter, Isabel, was returned as knight of the shire five times between 1365 and 1373. The many Essex properties eventually to fall to John included Heron, Downham, Beeches in Rawreth, Hockley and Ramsden Crays; and in 1422, on the death of his mother (who had married Sir Nicholas Haute of Wadden Hall, Kent), he also inherited the Tyrell manor of Avon in Hampshire along with other holdings in the New Forest. (However, her own lands in Cambridgeshire passed to his younger brother, Edward.)
Much of Tyrell’s wealth was accumulated from fees and annuities granted him by the magnates who engaged him as steward on their estates or in some other capacity. It seems likely that he received some training in the law which soon made him expert in estate management. By the time of his first return to Parliament he had formed important local connexions: he had begun what was to be a lifelong friendship with the lawyer Richard Baynard and a close association with Baynard’s brother-in-law, the former Speaker, John Doreward, ties which were strengthened when Doreward’s son, John, married his sister-in-law, Blanche Coggeshall. Tyrell witnessed the electoral indentures of 1411 which recorded his own return in the company of his father-in-law, Sir William Coggeshall (for whom he subsequently acted as a feoffee). Before he entered the Commons a second time he came into contact with Lewis John, the London vintner of Welsh extraction who could boast of important connexions at the court of the new King, Henry V. In April 1413, shortly before Henry’s first Parliament assembled, he provided financial securities for John on his appointment as master worker of the Mints; he subsequently assisted him in his acquisition of estates in Essex, and he was party with him to conveyances of property in the city of London on behalf of other vintners, most notably John’s friend, Thomas Walsingham.
Besides establishing a reputation for reliable service to local landowners, Tyrell began to be employed (usually as a surety) by men who played an important part in government, or who were close to the King. Thus, in May 1415 he was associated with Sir John Tiptoft (with whom he was long to remain on amicable terms) in entering bonds in 500 marks assigned to Thomas Langley, bishop of Durham, a transaction which probably had something to do with Tiptoft’s appointment as seneschal of Aquitaine. Among his co-feoffees of Oakham was Humphrey, duke of Gloucester, and on the eve of Henry V’s expedition to Normandy he joined the duke’s retinue, enlisting with five men-at-arms (including two of his own brothers) and 16 archers. He may well have already been engaged as steward of Gloucester’s estates in Essex. In July 1417 he assisted Tiptoft, a commander in the second expedition to France, when in association with the chancellor, treasurer and other important officials he received substantial loans from citizens of London towards paying the army’s wages. A year later Gloucester made him and Tiptoft, among others, mortgagees of a number of his manors to raise money for the payment of his debts. By then Tyrell had evidently become one of the duke’s most trusted retainers: in 1420 when Gloucester interfered in the dispute between Richard, earl of Warwick, and James, Lord Berkeley, over the descent of the barony of Berkeley, Lord James won his support ‘with his purse’ by being bound in 10,000 marks to Tyrell and Walter Sheryngton, clerk, ‘men whom the duke much trusted’, and by promising the duke himself lands worth 400 marks if he won his suit. Tyrell’s connexion with the King’s brother must have had some effect on the number of times he was returned to Parliament in the years following the victory at Agincourt. He is not known to have gone to France again during Henry V’s reign, although he was named on the list of knights and esquires of Essex sent to the Council in January 1420 as being most capable for military service.
In February 1422 Tyrell once again stood surety for Tiptoft at the Exchequer, and in May he did likewise for William Yerde, the attorney-general to John Holand, earl of Huntingdon (then a prisoner in France). In the Parliament which met that autumn (Tyrell’s seventh) he no doubt lent his support to Gloucester, then made Protector following the death of Henry V. Tyrell was appointed sheriff for the second time in 1423, as such holding the elections in Essex and Hertfordshire and making the returns for the former county of his friends, Richard Baynard and Robert Darcy. (He was to be closely linked to Darcy by the marriages of their children and grandchildren.) In November 1423 he provided securities for Ralph, Lord Cromwell, a member of the King’s Council,
Naturally, in view of his duchy office and his links with Gloucester, Tyrell’s connexions with members of the Council, such as Lord Tiptoft, continued, and his services as a mainpernor and feoffee were sought by such important landowners as Joan, Lady Beauchamp of Abergavenny, and John de Vere, earl of Oxford. In 1431 he became a trustee of the estates of (Sir) John Stourton II (afterwards Lord Stourton), and two years later he was named by Richard Baynard as an overseer of his will and by Richard Buckland†, the former treasurer of Calais and a retainer of the duke of Bedford, as an executor. Among the feoffees of his own estates were such prominent figures as Bishop Alnwick of Norwich and Ralph, Lord Cromwell.
Over the years Tyrell had assumed an important place in the management of the affairs of Richard, duke of York, rising from the of steward of steward of his inheritance at Clare and Thaxted to be receiver-general of all his estates. It may well have been at York’s request that in the Parliament of 1433 he had been one of the five men appointed to act as overseers of the administration of the effects of the late Edmund Mortimer, earl of March, whose nephew and heir the duke was; and in 1436 Sir John was involved as a feoffee in a mortgage of certain of the former Mortimer properties. His simultaneous attachment to both Gloucester and York presupposes some community of interest between the two magnates, who were, in fact, leaders of the party strongly in favour of an active prosecution of the war in France. Elected to his 13th Parliament early in 1437, Tyrell was chosen as Speaker for the third time, but on 19 Mar. (only eight days before the dissolution) he was replaced by William Burley, after being ‘par la visitation de Dieu’ stricken by various infirmities, ‘issint q’il ne purroit bonement entendre ne laborer sur et entour l’effectual esploitment de les basoignes de mesme le Parlement’.