In 1703, the manor and surrounding park was sold to Robert Heynsham, a Member of parliament and it remained within his family until 1833. In about 1869, it was sold to another parliamentarian James Sinclair, 14th Earl of Caithness.
The current manor was built in the 18th century, after a fire in about 1737. It has many 19th-century and later additions, including extensions to the rear and a porch on the west side. The main feature is the stuccoed south facade. The property was listed in 1968.
- "A History of the County of Hertford, vol 2". british-history.ac.uk. British History Online. Retrieved 24 September 2014.
- "Heynsham, Robert (1663-1723), of London and Stagenhoe". historyofparliamentonline.org. The History of Parliament. Retrieved 24 September 2014.
- "Stagenhoe Park (Sue Ryder Home), St Paul's Walden". britishlistedbuildings.co.uk. British Listed Buildings. Retrieved 24 September 2014.
- "Stagenhoe Park Certified Location". ukcampsite.co.uk. UK Campsite. Retrieved 24 September 2014.