It is a reasonable inference that John was a near kinsman of Robert Bertram, who represented Northampton in the Parliament of October 1383, and perhaps even his son. He first appears in the records in October 1414, when he was allegedly the victim of the theft of a horse, woollen thread and cloth to the value of £4 at Northampton.
Bertram’s career conforms to a pattern familiar among the borough’s MP’s, namely a single return to Parliament and a single term as bailiff as a young man. His interests, however, appear to have been more extensive than those of other prominent townsmen. From early in his career he had landed interests outside Northampton: in 1418 he had a plea pending against a husbandman for leaving his service at Brixworth, a few miles to the north. He may also have had trading interests in the capital, for in 1424, describing himself as a mercer, he sued the executrix of a London armourer for a small debt.
There is little other evidence about Bertram’s career. In 1434 he was distrained to answer the prominent Northamptonshire lawyer, William Alderwyncle*, for a debt of ten marks. Three years later he himself claimed £10 against a shipman of Sheringham on the Norfolk coast, and he clearly had business interests in that county, for it was there that a chapman of Banbury in Oxfordshire allegedly contracted a debt to him in twice that sum.
