The Haddon family had been established in Sandwich since the middle of the fourteenth century, when John Haddon, a royal serjeant-at-arms, was granted the office of bailiff by Edward III. Thomas was probably the son of Robert Haddon†, a local merchant who had been mayor and had represented Sandwich in the Parliament of 1410, or of his kinsman, another Thomas, who was an alderman and local shipowner.
By the close of 1432 Thomas was already one of the jurats. On 6 July 1435 he was elected as the town’s bailiff to the annual Yarmouth herring fair and 19 days later he was present when his appointment was confirmed at a meeting of the Brodhull. Fortunately for Haddon, and somewhat unusually, the Ports’ bailiffs were received in accordance with their liberties by the bailiffs of Yarmouth, who duly handed the keys of the town’s prison over to the Portsmen for the duration of the fair. Following their return home Haddon was present with his fellow bailiffs to report on their reception at a special meeting of the Brodhull on 16 Dec.
During the early 1440s Haddon was clearly one of the most respected members of the jurats’ bench. He attended six meetings of the Brodhull between April 1441 and October 1446 and in June 1442 he was chosen as one of the arbiters on behalf of the commonalty to settle the dispute over debts owed to the former mayor, John Green I*.
On his return from the final parliamentary session at Leicester in the summer of 1450 Haddon again resumed his local responsibilities and in December he was chosen once more as a jurat. The record of the municipal elections of the following year are not extant, but it seems likely that Haddon continued to serve as a jurat until his death. In July 1451 he was one of the six jurats who attended the first court of Shepway held by the new warden of the Cinque Ports, Humphrey Stafford, duke of Buckingham. On 20 Feb. 1453 he was named as one of the deputy mayors to John Nesham† and on the following 24 July he attended a meeting of the Brodhull.
Haddon appears to have married twice: together with his wife Constance in March 1446 he demised property in St. Mary’s Lane, Sandwich, to John Nesham and another jurat, Simon Leycestre; and his widow was named Joan.
