Of obscure origin, Lokton was perhaps related to the Yorkshire family of the same name.
It is possible that his association with de la Pole led Lokton to join the interest of John, Lord Tiptoft†, then the leading magnate in Cambridgeshire, for when Sir Walter died in July 1434 his heir was his young grandson, Edmund Ingoldisthorpe*, Tiptoft’s ward and soon to be son-in-law.
Within a year of her husband’s death, Tiptoft’s widow Joyce appointed Lokton her receiver-general, with a fee for life from the Cambridgeshire manor of Harston,
While clerk, Lokton remained active at a local level. In October 1452 he was on the grand jury which indicted those involved in a conspiracy by adherents of the duke of York at Cambridge and elsewhere in the shire the previous February,
Lokton remained clerk of the estreats until the end of April 1455. He was removed from office by none other than James Butler, by now earl of Wiltshire, who had succeeded Tipfoft as treasurer on the previous 15 Mar. He was not to regain the post following Tiptoft’s reappointment as treasurer in April 1462, or during Worcester’s brief third term as such in 1470, although he would return to the Exchequer in June 1462 to collect an assignment towards his recently re-installed patron’s fee.
A few months after losing office at the Exchequer, Lokton was elected knight of the shire for Cambridgeshire. The Parliament of 1455 was summoned in the aftermath of the Yorkist victory at the first battle of St Albans. Notwithstanding his membership of the grand jury three years earlier, Lokton must have followed the lead of his patron as far as political allegiances were concerned. By now Tiptoft was an ally of the duke of York, and it is likely that he exerted his influence to help his servant secure a seat in the Commons. Lokton could scarcely have stood for Parliament without Tiptoft’s backing, since he possessed no great landed wealth of his own. As recently as the beginning of 1451 he had been assessed as having a landed income of just over £11 p.a., less than the £12 he then earned in fees.
Not long after the Parliament dissolved, Tiptoft’s brother-in-law Sir Edmund Ingoldisthorpe died, having appointed Lokton as one of his executors. It was as such that he took out a pardon on 25 Jan. 1459,
During the 1460s Lokton was an estate officer for others besides the earl of Worcester. Between 1461 and 1464 he was steward at Sawston for John Sawston, and by 1467 he held the same position at Fen Ditton, a Cambridgeshire manor belonging to Tiptoft’s fellow humanist, William Gray, bishop of Ely. He may actually have held office in the episcopal liberty of Ely for some time before this date, since he attended the mass following Gray’s installation in March 1459,
The accession of the first Yorkist King did not interrupt Lokton’s role in local administration, in which his final appointment was a place on the Cambridgeshire commission of the peace of 10 Dec. 1473. Possibly already dead when that commission expired in November 1475, he was certainly no longer alive in August 1480.
