Nothing is known of Exton’s early background, although he may well have been a kinsman of the wealthy fishmonger Nicholas Exton†, who was twice elected mayor of London and played a prominent part in civic affairs during the early years of Richard II’s reign. Thomas Exton had established himself as a practicing goldsmith by May 1373 when he was made renter, or custodian, of all the property belonging to his livery company, and through a generous loan of 100 marks advanced while holding office in 1380 he made possible the purchase of a tenement in Newgate Street by his fellow goldsmiths.
Exton’s wealth and social position meant that his services as a mainpernor and feoffee were very much in demand, especially among other members of his guild. John Coraunt, a goldsmith accused of riotous assembly during the mayoral elections of 1384, called upon Exton to offer sureties on his behalf, as did John Edmond, a leading practitioner of his craft, who had to find mainpernors on being made engraver of dies at the Tower in 1389. Exton acted in this capacity for many other Londoners, including John Wade I, the fishmonger, at the time of his appointment in August 1403 as guardian of the daughters of the late Nicholas Exton.
Very little evidence has survived about the nature and extent of Exton’s commercial activities, although he was obviously rich enough to invest quite heavily in property. Only once, in August 1382, is he known to have supplied the royal wardrobe with goldsmiths’ wares (on this occasion 4,021 pearls worth 200 marks), although he may well have had other dealings with the Crown. He certainly had a connexion with John of Gaunt, whose receiver advanced him and two other Londoners a loan of 100 marks in 1391 and was repaid in the following year. The grant in January 1398 of a papal indult permitting Exton and his wife to make use of a portable altar is also a sign of the goldsmith’s social standing.
As his interests in property and finance grew, so Exton found himself increasingly involved in litigation. His first appearance in court took place in December 1376, when he gave evidence against a member of the Goldsmiths’ Company who had slandered him and the other wardens. Between November 1382 and November 1397 he was summoned as defendant in no less than eight lawsuits concerning the ownership of land and rents in the City. Two of these suits went against him, while the remainder were either dropped or settled more amicably out of court.
Despite the fact that he never held office as an alderman of London, Exton’s frequent election as warden of one of the most powerful city livery companies, together with his obvious financial expertise, made him a greatly respected member of the community. He was one of ‘the best and wisest men of the City’ chosen at a session of the common council on 24 June 1384 to examine the franchise and, more specifically, to consider changes to the notorious ‘Jubilee Book’ of ordinances compiled during the mayoralty of the radical John of Northampton†. The latter’s attack upon the monopoly exercised by the victualling guilds had at first won him many supporters, including a number of goldsmiths, but his extremism provoked the inevitable hostile reaction, in which Exton, as a common councillor, joined. In August 1384 he attended Northampton’s summary trial before the royal council at Reading, and in the following March he was one of the 24 citizens appointed during an emergency session of the common council to supervise the strengthening of the City’s defences against future disturbances. One year later, in March 1386, he was present at the meeting which pressed for Northampton’s permanent banishment from London by the King. Shortly afterwards the council nominated him to serve on a commission for the enforcement of a new rate of murage, intended to raise the money for more effective law enforcement. In November 1390 and again in June 1396, Exton, a former auditor of London, was appointed by the city chamberlain to examine the accounts of guardians entrusted with the property of young orphans.
Exton appears to have retired from public life in 1407, the date of his last term in office as warden of the Goldsmiths’ Company and of the one occasion on which he is known to have taken part in a parliamentary election at the Guildhall. He died between May and December 1420, and was buried in St. Paul’s churchyard. He made many generous bequests both to the cathedral and to the parish church of St. Leonard, London, which was promised the reversion of part of his estates on the death of Joan, his widow. Her will, drawn up on 5 Nov. 1423, refers to a daughter named Margery, although the latter probably predeceased Exton, who settled nothing on the child. He is also known to have had another daughter, Elizabeth, to whom Roger Elys left £5 in August 1395, but about whom no other evidence has survived.