The Earl of Derwentwater was beheaded in 1716, Parliament gave his estates to Greenwich Hospital, and in 1868 a woman calling herself his heir moved into the ruined castle

James Radclyffe, 3rd Earl of Derwentwater, grew up at the exiled Stuart court at Saint-Germain. He joined the 1715 Jacobite rising, was defeated at Preston and pleaded guilty. He was condemned in Westminster Hall on 9 February 1716 and beheaded on Tower Hill on 24 February. His estate, valued at £6,372 a year, went to the commissioners for forfeited estates. Later that year the family won a suit: the lands were entailed, so they belonged to his six-year-old son, John. John died unmarried in 1731. Parliament then voided the entail in 1732 and barred foreign-born children of traitors from inheriting English land. A 1735 act gave the income, then about £9,000 a year, to the Seamen's Hospital at Greenwich. The earl's brother Charles was beheaded in 1746. Charles's son, Lord Kinnaird, claimed the estates. The hospital refused, then paid him £24,000 and his siblings £6,000. It demolished Dilston Hall in 1765. In 1868 a woman calling herself Amelia, Countess of Derwentwater, moved into the ruins of Dilston Castle under tarpaulins. She said John had not died but had fled to Germany, and that she was his granddaughter. The hospital's receiver had her carried out in her chair. She camped in a roadside ditch, drew crowds, and urged tenants to pay her rent. Newcastle County Court made her bankrupt in 1871. She was jailed for contempt in 1872 and died poor in 1880. The Admiralty sold the estate to the Beaumont family after 1865. Cambian Dilston College now owns the castle.