Like his father before him, Kirton was an active and prominent member of the Southwark borough community, representing the town in Parliament on no fewer than four occasions. No details of his early life or education have been discovered, but in the light of his later career it seems likely that he underwent some legal training, perhaps – like his son after him – at Lincoln’s Inn.
At his father’s death in 1428 Kirton suceeded to his extensive landholdings: in 1436 his Surrey property alone was believed to give him an annual income of £20, and he apparently also had interests in the city of London and, by the time of his death, on its outskirts at St. Paul’s Cray in Kent.
From the 1440s, Kirton increasingly began to play a part in public affairs. In April 1440, for instance, he was named among the jurors inquiring into a dispute involving Peter Saverey*, and two years later he represented his neighbours in the Commons for the first time. In 1443 he was appointed as part of a commission of sewers along the river Thames between Lambeth and Newington, but it was at the very end of the decade, in the crisis years of 1449-50 that he became most active. In January 1449 Kirton was present in the Surrey county court for the elections of the shire-knights to the forthcoming Parliament, while later that year he was himself elected as MP for Southwark for the second time. By then, England was in turmoil as news came of the fall of the Norman towns to the French. On 4 Nov., two days before Parliament assembled, Rouen itself surrendered. During the Christmas recess, the keeper of the privy seal, Bishop Moleyns of Chichester, was murdered, and when the Commons reassembled in late January 1450 they launched an all-out assault on the King’s principal minister, the duke of Suffolk. On 17 Mar. Suffolk was banished from the kingdom, and two weeks later, Parliament was prorogued. London and its hinterland were seen to be too restless for the Lords and Commons to meet there again in safety, so on 29 Apr. they gathered at Leicester. Three days later, Suffolk was killed on his way to the continent, and before the end of May the entire south of England was in upheaval, with a Kentish rebel army camped at Blackheath threatening the capital. Parliament was hastily dissolved in the first week of June. When Kirton returned to Southwark, he probably found the Kentishmen under their leader Jack Cade roaming the streets of the borough, from where they were admitted to London on 4 July. The depredations of Cade’s followers in the City spelled the end of the whole enterprise, for the citizens were galvanized into asserting control of their streets, and – crucially – of London Bridge. Kirton’s whereabouts during the rising are unknown, but within two days he had availed himself of the royal pardon offered to those implicated in the rising. Yet whatever his actions during the summer months, he did nothing to alienate his Southwark neighbours, who re-elected him to the Commons that September. Nor was he regarded with suspicion in other quarters, for by Michaelmas he had entered into the service of Thomas Kempe, bishop of London, who appointed him bailiff of his liberties in Surrey and Sussex.
The later years of Kirton’s life were no less active, but in a somewhat different manner. While he continued to witness gifts and deeds in Southwark,
There is no concrete evidence of Kirton’s political sympathies or affiliations as the kingdom slipped into open civil war. Nevertheless, his return to the Parliament summoned in the aftermath of the Lancastrian defeat at the battle of Northampton in July 1460 may indicate that he was at least not seen as hostile to the duke of York’s cause. Moreover, following the removal of John Gloucester III* from office in July 1461, he was chosen a county coroner for Surrey, a post in which he would serve until his death three years later.
