A lawyer by profession, Warfield is first mentioned in 1408, when he was one of those by whom the sheriff of Hampshire summoned the parties in a land dispute to court. A few years later, probably in or before 1415, he became receiver and steward of the estates of the wealthy Stonor family, which were centred on the Chilterns. As such he served Thomas Stonor in this office from the time the latter attained his majority until his death in 1431. From the autumn of 1415 Warfield was also Stonor’s feoffee for such of his Gloucestershire lands as were placed in the hands of a syndicate headed by Robert Hallum, bishop of Salisbury, and Thomas Chaucer, and from the same time he also acted as a trustee of the family holdings in Berkshire. Subsequently, again in association with Chaucer, he was included among the feoffees of the Stonor manors of Ermington (Devon) and Penton Meysey (Hampshire) along with property in Westminster. Following Thomas Stonor’s death he continued as receiver of his estates, acting on behalf of his co-feoffees, Chaucer and John Golafre, until his own death in 1443.
It is clear that through most of his career Warfield kept in close contact with Chaucer, a cousin of the Beauforts, who held office as constable and steward of the castle and honour of Wallingford. Indeed, it was probably Chaucer, the guardian of the Stonor estates during Thomas Stonor’s minority, who had first involved him in the administration of those properties. Warfield, who had been present in the county court for Chaucer’s election to Parliament for Oxfordshire in the autumn of 1414, was early in 1416 made one of the trustees of the valuable manors in that county and Berkshire which the erstwhile Speaker had recently purchased from Sir Richard Adderbury II; and in the same year his help was also enlisted for his influential friend’s acquisition of the local estates which Sir Richard Camoys had inherited from Sir Gilbert Wace. In May 1420 he was Chaucer’s surety at the Exchequer when the latter obtained custody of the manor of Bradfield, and seven months later Chaucer appeared in the same capacity on his behalf, thus enabling him to take over the custody of certain mills at Wallingford. Then, in the following spring, Warfield acted as mainpernor for Chaucer at the Oxfordshire elections to the Parliament of May 1421 (in which he was to be chosen Speaker for the fifth time). When, in 1428, Chaucer purchased a manor in Berkshire from Thomas Poynings, Lord St. John, our MP was one of those named as attorneys for delivery of seisin. As we have seen, the association between the two men continued after the death of Warfield’s employer, Thomas Stonor. Indeed, under the terms of Stonor’s will, Chaucer, Warfield and John Hampden were to share control over the marriages of his children; and as longstanding feoffees, Chaucer, John Golafre and Warfield then administered the Stonor lands during the minority of the heir. After Chaucer’s death in 1434 Warfield apparently assumed joint control of the Stonor estates with Humphrey Forster, one of the latter’s own executors.
His exertions as Stonor’s receiver and Chaucer’s assistant apart, Warfield was also kept busy on behalf of other clients. In 1419 he had stood surety at the Exchequer for Sir William Argentine’s widow, and that same year he was retained for life as legal counsel by the commonalty of Henley at an annual fee of 10s. In the following year he was associated with the chancellor, Thomas Langley, bishop of Durham, and others in obtaining extensive property in Garsington and elsewhere in Oxfordshire, of which they were still acting as co-feoffees in 1427. In the early years of his career he attested parliamentary elections in Oxfordshire (doing so in 1414, 1419 and 1421), but thereafter his links were more with Berkshire.
Meanwhile, since 1430, Warfield had been serving as a coroner in Berkshire, and it was in his official capacity that he attended a number of county elections (those of 1431, 1432, 1433, 1435 and 1437, on each occasion being himself returned for Wallingford shortly afterwards). In 1434 he was among the gentry and notables of the shire who took the oath not to maintain breakers of the peace.