This MP is first mentioned in the spring of 1388, when he was a party to the conveyance of property near his father’s manor of Little Munden. As Sir John Thornbury’s only surviving son, he inherited a sizeable estate in Hertfordshire, which he and his widowed mother settled upon feoffees by a series of transactions begun in September 1396.
Thornbury’s connexions with the Durham family brought him into contact with a number of prominent local landowners, including (Sir) Thomas Charlton and his particular friend, John Ludwick, who made him one of his own trustees, and with whom he also acted as a feoffee-to-uses of John Durham’s property in the Hertfordshire village of Diggeswell. On becoming farmer of land in White Roding, Essex, in October 1399, Thornbury enlisted the services of both Ludwick and his father-in-law as mainpernors on his behalf at the Exchequer, while agreeing to act in the same capacity for them as lessees of property in Hertfordshire. He was also on close terms with Sir Edward Benstede, who married one of his sisters at about this time. The two men made a number of enfeoffments upon each other, although Benstede died first, leaving Thornbury to supervise the division of his estates and probably to execute his will as well. Sir Edward was involved with Thornbury in a far less creditable incident, which took place in 1403, and led to their indictment on a charge of conspiracy against one Thomas Molynton, who, it was alleged, had been imprisoned in Hertford castle as a result of the false accusations made by them against him. Being men of considerable influence in the area, they easily secured a royal writ of supersedeas. Once again, Ludwick and Durham came forward to offer sureties for them, and the case disappears from the record.
Meanwhile, as one of the administrators of his father’s estate, Thornbury faced a protracted lawsuit against the executors of William Gold, Sir John’s companion-in-arms, from whom he and his mother were eventually able to recover almost all the 4,200 marks owed to them. We do not know how successful they were in obtaining the additional sum of 2,000 marks which they claimed in damages, but it is clear that from 1398, at least, Thornbury was in possession of a considerable fortune. This is reflected in the grant to him, in February 1400, by Bishop Beaufort of Lincoln, of a licence to celebrate mass privately at the family home in Little Munden.
Sir Philip’s landed wealth, coupled with his reputation as a soldier, made him a prominent figure in county society, and it is rather surprising that he did not come to assume a more active role in administrative affairs. He was, however, in great demand as a witness to property transactions, most notably for John Hotoft of Knebworth, treasurer of the household to Henry VI.
Our Member’s dealings with the Armeburgh family, which seem to have occupied a considerable amount of his time between 1444 and 1453, are now difficult to understand, especially as the precise nature of his title to their extensive estates is by no means clear. In 1444, Joan and Robert Armeburgh settled their property in Warwickshire, Essex, Hertfordshire and Suffolk upon feoffees with a remainder to Joan’s ‘trusty friends’, among whom was Sir Philip, ‘here at all tymes true and faithfull kynnesman and friend’. By July 1452, he and Reynold Armeburgh, who also possessed a reversionary interest in the estate, were at odds with Ralph Holt over the question of ownership, and then offered him recognizances of 100 marks as a guarantee of their readiness to submit the matter to arbitration. The dispute was settled in their favour, but there is a strong possibility that Thornbury had been acting as a trustee for one of the other parties. He had certainly relinquished any title to the Armeburgh estates in Hertfordshire by 1456, for a settlement of all his holdings then made upon his only daughter, Margaret, does not even mention them.
Save for this lawsuit and an unspecified disagreement with a husbandman at Cheshunt, Thornbury spent his last years in quiet retirement at Bygrave. An interesting light is shed upon his household there by indentures drawn up in 1448 between him and his cook, Richard Whiturk. According to his terms of employment, Whiturk was to receive a fee of 20s. p.a., clothing, fuel and a tenement at Little Munden, free of rent, for the rest of his life. He, for his part, undertook to serve Thornbury and his wife as ‘larder, catour and cook’ for as long as they both lived.
Thornbury was already well over 70 when he made his will on 25 June 1452, although he lived on for another four years or more, dying shortly before February 1457. He was buried beside his wife in the parish church of Little Munden, where their tomb with its impressive effigies may still be seen. He had at least two sons, Richard and Thomas, both of whom predeceased him; and it is possible that the John Thornbury who went to France with Henry V in 1420 was another of his children. All Sir Philip’s estates descended to his only surviving daughter, Margaret, and her husband, Nicholas Appleyard.