Belhus mansion was the home of the Barrett-Lennard family. The house was visited by Queen Elizabeth I in 1578. Belhus was among the properties owned by Dorothy, Lady Dacre, after the death of her husband. After her own death, an inventory was taken of her possessions at Belhus. A 17th-century curtain from Belhus was donated to the Victoria and Albert Museum by Mrs John Pollock, daughter of Sir Richard Barrett-Lennard, 5th Baronet.
In the middle of the 18th century, the mansion was substantially altered to conform to the fashionable “gothic” style. Thurrock Museum has a 19th-century copy of an earlier original painting showing how the mansion looked around 1710.
Among the family portraits at Belhus was a work by Hans Eyworth – Mary Neville, Baroness Dacre – now in the National Gallery of Canada. This was seen at Belhus in 1761 by the art historian, Horace Walpole.
The Barrett Lennard family auctioned the contents of Belhus in 1923 and the house was demolished after World War II, due to suffering bomb damage as well as vandalism from the military personnel who were stationed there. The mansion gave its name to the manor of Belhus.