Blackstone fell into debt, largely because of the building costs, which resulted in him spending time in the debtors' prison at Oxford and contributed to the end of his political career.
[1] Other owners of Howbery Park were Henry Bertie Williams-Wynn (who purchased the house in 1867), Harvey du Cros (in 1902) and George Denison Faber, 1st Baron Wittenham.
The estate passed into the ownership of the government in the 1930s and was used during the Second World War to house US and Canadian servicemen and then refugees from Central Europe.
In addition to HR Wallingford who occupy a new building, Kestrel House, several other organisations are now based in Howbery Park, including the Environment Agency.
Several drivers on Benson Lane, adjacent to Howbery Park, claim to have been forced to swerve to avoid a lady dressed in grey who was walking in the road.