The attic storey was extended and other alterations made for John Bligh, 3rd Earl of Darnley by Sir William Chambers, ca 1767–70[4] A kitchen court was added to the rear in 1771–73.
[6] John Bligh, 4th Earl of Darnley, who inherited in 1781, employed James Wyatt extensively, for interiors that included the picture gallery and the dining room, and for stables and a Gothic dairy.
[9] Their father, Humphry Repton, was hired to design a landscape plan for the estate and completed one of his famous "Red Books" for Cobham in 1790.
A scene in Agent Cody Banks 2 in which Frankie Muniz fights Keith Allen in a room full of priceless treasures was filmed in the Gilt Hall.
The hall is used as the Abbey Mount school in the 2008 film Wild Child starring Emma Roberts, and as the Foundling Hospital in the CBBC adaptation of Hetty Feather.