Treouran, who came from a family which held estates in the west of Cornwall, appears to have been normally resident at Truro. The extent of his property, which included the manors of Gwarnick (in St. Allen) and Namboll (in St. Keverne), as well as scattered holdings in the parishes of Paul and Ludgvan, is otherwise obscure, but in 1451 his annual income was said to amount to £5.
Nothing is known of the background to Treouran’s return to Parliament for the county town of Lostwithiel in 1437, although there may be some significance in the presence among the electors in the county court of his putative kinsman Roger Treouran I*, who was to rise to prominence as a county coroner not long after.
.Like many other south-westerners John Treouran had shipping interests. He owned a share in Le Marie of Truro, a vessel of 40 tons, which he and his partner Thomas Poldu were licensed to take to Santiago in August 1462,
By the early 1460s Treouran, who in September 1449 was said to be over 50 years old, was clearly a respected member of the community of Truro, and within a few years his standing led to his election as mayor of the town. It was in this capacity that he presided over the parliamentary elections in the borough in May 1467 and attested the borough’s indenture with the sheriff, Sir John Colshull*.
