Nevill succeeded to the peerage in the autumn of 1662.
Money, which had been the previous holder’s greatest preoccupation, also proved to be Abergavenny’s principal concern during his brief tenure of the barony. He succeeded to a depleted estate following the land sales presided over by his brother, though he retained land in Kent, Worcestershire, Oxfordshire, and Warwickshire.
In common with a number of other Catholic peers, Abergavenny appears to have aligned himself with the opposition to Edward Hyde, earl of Clarendon, and on 13 July Philip Wharton, 4th Baron Wharton, listed Abergavenny among those who he believed would support Clarendon’s impeachment.
Abergavenny took his seat in the new session on 2 Apr. 1664. He attended on 61 per cent of all sitting days and on 21 Apr. he was named to the committee considering the bill against gaming. He sat for the last time on 17 May. On 23 Nov. he entrusted his proxy to Northampton, which was vacated by the close of the session on 2 Mar. 1665.
On 29 May 1666 Abergavenny composed his will, in which he devised his manors of Birling and Huddesdon in Kent to his daughter, Winifred (there seems only to have been one daughter, though she is referred to also as Bridget or Mary). She later married her stepbrother, Sir John Shelley of Michelgrove.
