Castle is built on the site
of the Palace of Seton,
which formerly belonged to the Earls of Winton, and which was demolished in 1789 after 75 years of neglect. The
estate of Winton included the barony and burgh of Tranent until the last
Earl, George Seton, fifth Earl of Winton,
lost his titles and estates for participating in the 1715 Jacobite
rebellion. Winton was condemned to death but managed to escape the
Tower of London, living the rest of his life in Rome where he died
in 1749 as a member of Chevaliers’ Cabinet. The old
Palace was often regarded as the most desirable Scottish residence
of the 16th and 17th centuries and was frequently visited by
royalty including Mary Queen of Scots, James VI and Charles I.
By the 1790's the
Palace was a ruin, and the site in the hands of Lt Col Alexander
Mackenzie of the 21st Dragoons, eldest son of Alexander MacKenzie
of Portmore, Peebleshire. He was a young man in his early twenties
when he commissioned the design, though he would not live long to
enjoy his new house as he died five years later in 1796, at which
point the Earl of Wemyss acquired the estate.
Robert Adam was
commissioned to design Seton Castle in the summer of 1789. By
December the design was at the stage of working drawings and the
building contract was awarded to the builder Thomas Russell and
was constructed between 12 November 1789 and the summer of 1791.
John Patterson, Robert Adam's Clerk of Works in Scotland, (later
to become a competent architect in his own right) reported to Adam
in a letter of 26 April 1790 that the old building had been
demolished and cleared. Of course the demolition of Seton
Palace provided a ready supply of stone and extensive use was made
of this. Robert Adam, on his last visit to Scotland before
his death, dined with his client in the new house on 11 June 1791.
The "new" Castle is a Grade A Listed
Castellated late Georgian House, one
of the most striking of Robert Adam's late houses in the castle
style, it is made up of various shaped towers around a curved wall
enclosing the courtyard which is entered by a central archway.