Despite his long period of involvement in the business of local government, the subject of this biography remains a shadowy figure about whom little evidence has survived. He is first mentioned in July 1378, when William Pensax, the vicar of Oakham, who was almost certainly a near relative, chose him to execute his will. He was assisted in this task by his neighbour, William Flore, whose son, Roger, appears to have been one of his closest friends. Probably because of their earlier complicity with William Pensax in the seizure of an estate in the Nottinghamshire village of Sutton, at least four of our Member’s kinsmen spent part of the early 1390s in prison, both in the Tower of London and at Nottingham castle, although he himself did not share their misadventure.
Although he did not derive as much personal benefit as his friend Flore from the Lancastrian usurpation, Pensax clearly prospered because of the change of regime. Within less than one year of Henry IV’s coronation he obtained a seat on the local bench, began to serve on royal commissions and became sheriff of Rutland. His first return to Parliament followed in January 1404, and in the same year he and Thomas Thorpe, his colleague in the House of Commons, agreed to act as trustees of some Essex property in which Sir Thomas Oudeby had an interest. Shortly afterwards, Roger Flore made Pensax a feoffee-to-uses of certain land which he had just acquired in Oakham. At some point before June 1409, he became involved in a dispute which appears to have taken a violent turn, for he was then bound over in sums of £10 to keep the peace towards a Londoner named Richard Yonge.