Publications
Will of Sir William Percy, by Unknown Author(s), published 1920 in Sussex Archæological Collections (vol. 61, notes & queries, pp.144-145) accessible at: W.S.R.O. [Lib 2146] & The Keep [LIB/500279] & S.A.S. library View Online
A Percy Heiress: A Page of Petworth History, by P. D. Mundy, published 1930 in Sussex County Magazine (vol. IV no. 7, article, pp.559-562) accessible at: W.S.R.O. [Lib 2308][Lib 2309] & The Keep [LIB/500173]
Sussex and the U.S.A. 6 - Sussex and the Hon. George Percy, adventurer to Virginia, by David McLean, published 1930 in Sussex County Magazine (vol. IV no. 7, article, pp.602-608; no. 8, pp.650-654) accessible at: W.S.R.O. [Lib 2308][Lib 2309] & The Keep [LIB/500173]
The Estates of the Percy Family, 1416-1537, by J. M. W. Bean, 1952 at Oxford University (D. Phil. Thesis)
The Household Accounts of Henry Percy, Ninth Earl of Northumberland, by G. R. Batho, 1953 at University of London (M.A. thesis)
Ars longa, vita brevis: the Watteau study and Lord Percy by J.M.W. Turner, by Gerald Finley, published 1981 in Journal of the Warburg and Courtauld Institutes (vol. 44, article, pp.241-247)
Petworth House.
The Wizard Earl's Advices To His Son, A Facsimile and Transcript from the manuscripts of Henry Percy Ninth Earl of Northumberland at Petworth House, by Gordon R. Batho, published 2002 (The Roxburghe Club)
The retirement of Henry Percy, ninth Earl of Northumberland, at Petworth 1621-1632, by Gordon R. Batho, published 2009 in Sussex Archæological Collections (vol. 147, article, pp.147-152) accessible at: W.S.R.O. [Lib 17254] & The Keep [LIB/500365] & S.A.S. library View Online
Abstract:Henry Percy was released from incarceration in the Tower in 1621 by the influence of James Hay, a favourite of King James who had married Lucy, the Earl's younger daughter, against his wishes. He was at first confined to 30 miles from Petworth, but the restriction was later removed. He was not, however, allowed to attend Parliament even when Charles became king. Algernon, his heir, was called as Baron Percy. The Earl lived quietly, often visiting his older daughter Dorothy, wife of Viscount Lisle, and her children at Penshurst. Northumberland died at Petworth on 5 November 1632, the anniversary of the Gunpowder Plot which had caused him so much grief, though he was clearly innocent.