There are many design proposals dating from c.1770 for both the house and grounds. The designed landscape at Dalmeny was laid out following the construction of the new house in 1815-1820, following a plan by Thomas White Jnr dated 1815.
Barnbougle Castle was built by the Mowbray family in the 13th century. It was acquired in 1662 by Sir Archibald Primrose whose family, originally from Fife, can be traced back to the 15th century. The Earldom was conferred on Sir Archibald's son in 1703. The 2nd Earl succeeded in 1724 but in 1755 he was bankrupted and the estates were managed by Trustees. Roy's map of c.1750 indicates the composition of the designed landscape in the closing years of the 2nd Earl's life. Its main features then were two avenues, centred on Barnbougle Castle; one leading west and the other south, with some wooded enclosures on either side of these avenues.
The 3rd Earl, Neil, inherited the estates in 1755 and soon after embarked on a Grand Tour of Europe which lasted some 18 months. In 1774, he commissioned his friend of longstanding, Robert Adam, to design a new house to replace Barnbougle, the drawings of which are retained by the family. Robert Burn was also asked to prepare plans in 1788 but neither scheme was carried out. Several proposal plans were drawn up at this time for the landscape also. The 3rd Earl spent most of his life regaining and putting right his estates and particularly in planting and replanting the woodlands. He also built a new walled garden in the late 18th century; the walls were heated by a complicated system of fires and flues. Some repairs were made to Barnbougle in 1789 but, otherwise, contemporary views describe it as being somewhat neglected at the end of the 19th century.
In 1805, shortly after his marriage, the 3rd Earl's son commissioned William Atkinson to prepare plans for a house, and later asked William Burn to prepare some plans in c.1808. Again these plans were turned down by his father, and the heir and his wife rented Duddingston House as their home until they inherited the Dalmeny estate in 1814. Immediately, the 4th Earl, Archibald, commissioned Jeffrey Wyatt to design his much anticipated new house but the plans were passed to William Wilkins, a friend, who produced the final design. The designed landscape was laid out in conjunction with this house, starting from 1812, based on a plan by Thomas White Jnr, thought to have been designed originally for a classical house.
The 5th Earl, the present Earl's grandfather, inherited the estates in 1868. He married Hannah, the only daughter of Baron Meyer de Rothschild. Influenced by visits to America, they established the arboretum to the west of the house and planted various exotic softwoods elsewhere, mainly in the garden valley. Lady Rosebery was responsible for establishing species in the understorey of the arboretum, contributions for which were received from cousins who owned the Exbury nurseries. The 5th Earl was Prime Minister from 1894-95 and did not spend much of the year at Dalmeny. He was responsible for the construction of a new drive and a lake. The 6th Earl inherited in 1929. The 7th Earl and Countess inherited in 1974; by that time, they had been involved in the estate management for some ten years and have continued to improve the estate, particularly the woodlands and parks.