The formal landscape which existed around Keith Hall in the 18th century was extended in the informal style following an improvement plan prepared by Thomas White in 1794 for the 6th Earl of Kintore. Some further improvements were made by the 8th Earl between 1844-80 and again by the 9th Earl between 1895- 1914. The gardens have been restored since 1985.
In the early years of the 14th century, Sir Robert Keith received grants of lands which were forfeited by the Earls of Buchan. Sir William Keith later received large areas of land in Kincardine and Aberdeenshire through his marriage to the heiress of Sir John Fraser. Lands in Fife were also added to the Keith estates in exchange for the Barony of Dunottar.
Sir William Keith was created Lord Keith between 1446-51 and, in the latter years of the 1450s, he was created Earl Marischal and Lord Keith. In 1651, the Regalia of Scotland was saved from the siege of Dunottar by the youngest son of the 6th Earl Marischal, the Hon Sir John Keith. It was in recognition of this that he was later created 1st Earl of Kintore in 1677.
In 1662, Sir John married Margaret, daughter of the Earl of Haddington. The following year, they bought Caskieben Castle, which was renamed Keith Hall. Some repairs were carried out soon after Sir John purchased the Castle but major work did not begin until the latter years of the 17th century. Some planting is known to have been carried out, notably of elm and laburnum.
The 1st Earl died in 1715. The 2nd Earl lived only until 1718 and was succeeded by his son John. In 1729 he married and work recommenced at Keith Hall but with limited finances. William Adam was commissioned but his plans for remodelling the remainder of the house were not carried out. By 1751, it is recorded that planting established by the 1st Earl had become neglected. Roy's plan of c.1750 indicates the presence of a simple, formal landscape by the mid-18th century. A survey plan of 1781, not studied in the course of this research, shows formal avenues converging on the house from the south and east indicating that the 4th & 5th Earls of Kintore made no major changes to the landscape.
In 1778 the 5th Earl died. The title of Earl of Kintore and the estates passed to Anthony Adrian Falconer, 8th Baron Falconer, through his great-aunt, Catherine, the daughter of the 2nd Earl of Kintore who had married the 5th Baron Falconer in 1703. By the time of his succession, Keith Hall had been empty for seventeen years and the 6th Earl commissioned the interior to be refurbished despite the fact that his main home was at Inglismaldie, Kincardineshire. In 1788, architect John Paterson was commissioned to carry out major alterations. In 1794 Thomas White prepared a plan for informal improvements to the landscape. Between 1806-12, architect John Smith was employed to build new stables and to alter the existing offices. A new bridge was built as well as the kennels and stables. Work ceased on the death of the 6th Earl in 1812.
The 8th Earl of Kintore, Francis Alexander, inherited Keith Hall in 1844. David Bryce was commissioned to prepare plans for alterations to the house which were published in 1851 but the extent of the work actually carried out to his design is uncertain. William Ramage of Aberdeen submitted estimates for work in the garden in 1853. The following year, the house was altered by him, the garden laid out and the North Lodge built. It has been suggested (Giles Worsley, CL, May 28th 1987) that the 8th Earl had plans prepared by well known architects but the actual work was executed by Ramage.
The 9th Earl succeeded in 1880. Between 1889-95, he was Governor of Australia but, on his return to Keith Hall, he commissioned alterations to the offices and south elevation of the house. Architect Sydney Mitchell prepared some plans but James Garve & Sons of Aberdeen were also involved in 1903. The 9th Earl improved the gardens and created the lake to the south of the house. In 1914 however, his trustees sold the estate which, at that time, extended to some 17,126 acres (6,936ha). The house and a small part of the original estate was repurchased by the 9th Earl and inherited by his son, the 10th Earl, in 1930.
The 10th Earl married Helena, Duchess of Manchester, in 1937 and, soon after, the interior of the house was almost completely remodelled. The present 11th Earl of Kintore inherited Keith Hall in 1966. His son, Lord Inverurie, lived there for some time before moving to the converted stables. In 1984, the house and some 25 acres (10ha) of immediate gardens were sold to Mr Kit Martin. He, with the assistance of architect Douglas Forrest, has carried out a major restoration of the house and has converted it into separate apartments. The garden is now owned by Keith Hall Gardens Ltd which was formed to restore and maintain the gardens for the benefit and use of the owners of the house.