ONSLOW, Henry (1627-67), of Slinfold, Suss.

As the second surviving son of the wealthy and able Sir Richard Onslow, it seems likely that this MP enjoyed at least some higher education or travel to match the university and inns experiences of his elder brother Arthur, although no direct evidence of this has come to light. It is also unclear at what date he was endowed with the estate at Slinfold bought with other local property by his father in 1634.13Coventry Docquets, 653; PROB11/314/335. It seems probable that, if he was not established there before his marriage in July 1656, he had been given substantial maintenance or opportunities to better himself: Sir Richard left £1,000 each to two of his younger sons, one of whom had also been placed in an apprenticeship.14PROB11/314/335. None the less, two marriages in fairly quick succession to women who brought large portions or inheritances helped him to consolidate his position in Sussex. Nomination as an assessment commissioner and appointment as a justice of the peace followed his first marriage to the daughter of a local ironmaster.15A. and O.; C231/6, p. 387.

Onslow’s election to the 1659 Parliament for Arundel, about 18 miles south west of Slinfold, almost certainly stemmed from his family’s long and close association with the Howard family.16HMC 14th Rep. IX, 483; s.v. ‘Onslow, Sir Richard’. However, his father’s pre-eminence in the region may also have played a part and Sir Richard was perhaps keen to have two sons in the Commons while he was in the Other House. In practice Onslow was overshadowed by his brother Arthur, by this time a seasoned and confident Member. If the ‘Mr Onslow’ of the Journal and Thomas Burton’s* diary was always the latter, as seems almost certain, then this MP made no discernible impact on proceedings.

Onslow continued to hold local office and to expand his property after the Restoration.17C181/6, p. 58; SR. He was knighted at Whitehall in May 1664.18Shaw, Knights of Eng. ii. 239. He died some time before 23 November 1667, when administration of his estate was granted to his widow.19Surr. Arch Colls. vi. 55; xxxiii. 183; PROB6/42/142. His grandson Denzil Onslow† of Mickleham entered Parliament for Guildford in November 1740.20HP Commons 1715-1754.