This MP may have been the son of the John Kirkby who was a party to property transactions in the Essex manors of Mucking and Tillingham at the very beginning of the 15th century, and who had, perhaps, when young, served in the retinue of John of Gaunt.
Kirkby had by then already been acting as marshal of the Exchequer for five years, on the nomination of John Mowbray, the Earl Marshal, to whom he owed his initial advancement. It was, perhaps, in an official capacity that he sued one John Saxeby of Surrey, in 1416, for a debt of £10. His position as an employee of the Exchequer probably helped him to establish a reputation in Hertfordshire, and from 1419 onwards he was in considerable demand among his neighbours as a mainpernor. Later in the same year he attended the election of knights of the shire held at Hertford; and it is interesting to note that his own return to the Parliament of December 1421 was witnessed by one Richard Kirkby, who may well have been a relation.
We cannot tell how much property Kirkby held during his early life, because some of the estates listed in his inquisition post mortem clearly belonged to his second wife, Joan, whom he did not marry until the early 1430s. Even so, while her predecessor was still alive he owned the manor of Gacelyns and farms in Bishop’s Hatfield, together with land in both Little Hadham and across the county border in the Waltham area of Essex. These holdings, as well as tenements in Birchin Lane, London, were released to John and Elizabeth Kirkby in July 1429 by John Marwe, who may have been our Member’s brother-in-law. Kirkby’s purchase of a fishery and marshland at Waltham Holy Cross in 1424 was probably intended to consolidate his other possessions, and explains his subsequent inclusion on two commissions of kiddles on the river Lea. By the time of his death, he had also acquired the manor of Ponsbourne, and appurtenances in the Hertfordshire villages of Ashwell, Hinxworth, Berkhampstead and Essendon. According to the tax returns of 1436 his property in this county alone was worth £40 a year, although his total annual income from land must then have been far higher. From 1435 onwards Kirkby systematically conveyed his Hertfordshire estates to feoffees, including John Fray, Sir Philip Thornbury and his close friend, John Barley. His land in Essex was either sold or likewise settled upon trustees, but the nature of this particular transaction, which took place in 1441, is not entirely clear.
Kirkby lived the life of a country gentleman, becoming involved as both a witness and a feoffee in the disposal of his neighbours’ property. It was probably in the latter capacity that he was summoned to appear as defendant in an assize of novel disseisin held at Chelmsford in the spring of 1423. He seems to have been on close terms with William Rokesburgh, for whom he offered sureties at this time as the farmer of John Baud’s property in Essex and Hertfordshire. Kirkby also agreed to accept the trusteeship of Rokesburgh’s personal effects, and in January 1430 the two men appeared together as mainpernors at the Exchequer and trustees of property in London. Evidently retaining an interest in the Baud estates after his friend’s death, Kirkby was made a feoffee of the manor of Mark Hall in Essex by Edward Tyrell† in November 1439. He performed a similar office for other prominent local landowners, including Joan, the widow of Sir Bartholomew Bacon, and John Barley, although the latter outlived him and had to find another trustee.
Kirkby died on 18 Oct. 1443, not very long after his second wife. They had one child, a daughter then aged four, about whom nothing else is known. The sale of part of her inheritance to (Sir) John Fortescue four years later suggests that she probably died young.