Nothing is known of Knightley’s family background. If he was related to Richard Knightley*, a prominent member of the local gentry, their relationship has left no trace on the records. He first appears early in 1415 when he entered into a bond in £20 to Richard Napton, prior of St. Andrew, Northampton, as surety for the farmer of a water-mill belonging to the priory. Five years later, in 1420, he appeared in person in the court of King’s bench to sue for trespass a weaver from Holdenby, near his home town, and a husbandman of Kelmarsh in the north of the county.
Knightley’s commercial interests were more varied and extensive than the description of ‘baker’ implies. Although his election to Parliament came early in his career, it did so when he already had sufficient capital for speculative ventures. On 14 Mar. 1423 he purchased from Mary, the mother of Sir Thomas Green*, for the sum of 50 marks, all ‘underwode and shredynges’ of trees in 44 acres of woodland in Greens Norton, and followed this a few weeks later by undertaking to buy for a further £45 specified timber growing there.
It is clear from his two appointments as a royal tax collector and his connexions that during the 1430s Knightley numbered among the leading townsmen of Northampton. When attached to answer the prior of St. Andrew in 1431 on a plea arising out of the bond of 1415, he was able to call on John Bertram*, another of the town’s former MPs, as surety, and two years later he himself offered mainprise for John Spriggy† and John Bosworth*, other former MPs, in the court of King’s bench. He also seems to have been one of Spriggy’s feoffees in property in Far Cotton and Hardingstone on the outskirts of the town.
In the mid 1440s Knightley was put to the expense of several distraints on his failure to answer two important plaintiffs on pleas of trespass: one sued by Lionel, Lord Welles, and the other by Simon Kynnesman† of Loddington. Such actions explain why, as ‘of Northampton, baker alias baxter’, he sued out a general pardon on 1 Sept. 1446.