Representing a junior branch of the Trefusis family of Mylor which had settled at Landew by the 1580s, Trefusis inherited estates scattered across Cornwall while still a minor. He escaped wardship due to the precise tenure of those lands which he held from the Crown, a situation which the duchy of Cornwall unsuccessfully challenged in 1616-17, and his mother apparently acted as his guardian until he came of age. A further bequest of property from an uncle in 1612 boosted his eventual inheritance to more than 2,500 acres, including five whole manors and a share of eight others. However, nearly 800 acres, embracing two of these manors, were held until 1638 by his widowed aunt, who subsequently married Ambrose Manaton*, while Trefusis’ mother, who was still living in 1629, had as her jointure 750 acres and the mansion at Landew.
In March 1628 Trefusis was elected to Parliament for Newport. Although he owned land close to the borough, he owed his place to Eliot, who nominated him after declining the offer of a seat himself. Because the vote for the second burgess-ship was disputed, Trefusis was initially barred from the Commons, despite Eliot’s protests on 22 March. However, he was provisionally admitted eight days later, and the legitimacy of his return was confirmed by the House on 14 April.
Trefusis’ tendency to resist the Crown’s arbitrary financial demands persisted during the 1630s, as he refused either to pay a knighthood composition fine or to contribute to the king’s Scottish campaign in 1639.
