He is first mentioned in June 1351 in a papal register of
indults issued to inhabitants of England, where he is called a "
clerk, of the diocese of
Salisbury" in
Wiltshire. He next appears in 1353 as a member of a commission to survey
Battle Abbey. This commission was followed by an extensive number of others, as evidenced by extant
patent rolls, until 1388, most of which related to
oyer and terminer, ,
gaol delivery, sewers, and the peace primarily, but not exclusively, in
Kent and other parts of southeastern England. He was appointed a
Justice of the Peace for Kent on 18 May 1362, and at the same time began serving as legal counsel. In July 1362 he served on a commission with
William of Wykeham investigating lands granted to the
Bishopric of Winchester, which Wykeham at that time held. From this point Belknap's career as a lawyer began to prosper; from 1371 he was retained as a lawyer by
Westminster Abbey, and from 1374 by
John of Gaunt. He was sent along with
John Wycliffe and
John Gilbert to
Bruges in July 1374 to negotiate papal provisions; he returned in September and on 10 October he was made
Chief Justice of the Common Pleas, and was
knighted on 28 December of that same year. From 1375 to 1388 he served as a Trier of Petitions in Parliament, and in 1376 he was involved in investigating
Richard Lyons in Essex and
Sussex after complaints of embezzlement. Following the death of
Edward III he was reappointed as Chief Justice under
Richard II but was widely unpopular; at the time of the
Peasants' Revolt he was in Essex conducting a court of
trailbaston and was forced to promise not to conduct such courts again, as well as physically attacked. When the rebels reached London he was one of 15 people whose deaths they demanded. He also offended the people of London itself by suggesting that their claim to the position of
Chief Butler of England for Richard's coronation should be rejected; in response they placed a model of his head on a water fountain in the marketplace so that it would vomit wine when Richard walked by. Belknap's downfall began when he advised the commission created in Parliament on 19 November 1386 to reform the government. The king and his advisers saw this commission as infringing on royal authority, and on 25 August 1387 Belknap and the other justices involved were summoned to
Nottingham and asked whether such a commission was lawful and, if not, how the summoners should be punished. The justices responded that such a commission was unlawful, and that the summoners should be punished as traitors. Belknap reportedly refused to seal the answers until threatened with death by
Robert de Vere, Duke of Ireland, and
Michael de la Pole. In response to this the
Lords Appellant seized power on 17 November. After the
Merciless Parliament began on 30 January 1388
Robert Charleton was made Chief Justice of the Common Pleas, and Belknap was arrested along with his fellow justices. The group were brought to trial on 27 February due to their answers in relation to the legality of the parliamentary commission, and were sentenced to death. After many high-ranking figures including
William Courtenay and
Queen Anne pleaded on their behalf, the sentence was changed to that of forfeiture and
attainder, including exile to
Drogheda, Ireland. At the time of his attainder, Belknap held extensive manorial properties in Kent (
Beachborough Manor,
Orpington, Seintling or
Saint Mary Cray, Bybrook Manor, Westcombe Manor, Kingsnoth, among others),
Sussex (Knelle Manor, Wilting Manor), Hampshire (
Crux Easton,
Penton Mewsey),
Hertfordshire (
Rushden, La More Manor),
Cambridgeshire (
Gamlingay,
Caldecote,
Norfolk (
Salthouse),
Bedfordshire (Little Holwell), and
Oxfordshire (Hoo Manor). The attainder and exile were revoked in the January 1397 parliament. Some of Belknap's land holdings were returned to him or members of his immediate family with the first parliament of
Henry IV in October 1399, although his wife Juliana in a noted case was allowed to bring suit as
feme sole for certain lands. Belknap died less than two years later on 19 January 1401, and was buried in
Rochester Cathedral. ==Family==