Not always easy to distinguish from his father, John is first heard of in the mid 1430s. In August 1435 he and the elder John Welsbourne attested the return of the MPs for Wycombe to the Parliament of that year, and a few months later he was party to the conveyance of a messuage and its appurtenances in Wycombe, apparently on behalf of Walter Kyppeloue and his heirs.
By 1450 John was himself a royal servant, for it was as a yeoman of the Crown that he had received letters patent of October 1445, granting him a daily fee of 6d. for life from the issues of Oxfordshire and Berkshire.
As a royal servant who was also from Wycombe, Welsbourne was an obvious candidate to sit for the borough in two successive Parliaments. In the first of these assemblies, summoned so that the government could bring down its opponent, Humphrey, duke of Gloucester, he was part of a larger than usual Household contingent in the Commons. By the time he re-entered the Commons, however, the government was far less in control of events, and in the next Parliament, that of November 1449, the King’s unpopular chief minister, William de la Pole, duke of Suffolk, was impeached. Following Suffolk’s downfall and death, the Parliament of 1450 attempted to recover some of the resources which the King had so foolishly lavished on his servants with an Act of Resumption. In the event this was easily circumvented, even by minor Household men like Welsbourne. He and another lesser royal servant, John Redeshull (perhaps the Wycombe MP of 1442), were able to obtain an exemption covering any grants which either of them had received from the Crown, provided that none of these was worth more than £10 p.a.
There is no way of knowing whether John participated in any of the armed conflicts of this period, although at the beginning of 1461 the government, still under Yorkist control, issued a commission for his arrest.
Four years later, Welsbourne made a brief will, dated 6 Sept. 1465. He asked to be buried in the church of St. Mary Wolnooth in London, to which he left 6s. 8d., and appointed two executors, his wife Cecily and son Thomas. He was dead by 10 Feb. 1466 when the will was proved.
