The surrounding lands were in the possession of the Clan Buchanan from at least 1231, but the direct chiefly line failed in 1682. Cousins of the Buchanan family, the Du Bruls, are the remaining family. Significant debt had been inherited by
22nd Chief John Buchanan and during his chiefship, the Buchanan estate was gradually sold to satisfy creditors. The estate was bought by the
3rd Marquess of Montrose (1657–1684), whose son became
Duke of Montrose in 1707. The Montrose family occupied the existing Buchanan Auld House and this eventually replaced
Mugdock Castle as the seat of Clan Graham, being seen as a dwelling more fitting the title of marquess. The original house was named Buchanan Place and substantially rebuilt from approximately 1724. It was altered in 1751 by John Adam and considerably enlarged in 1789 by William Playfair, giving it an extensively grand principal front near 300 feet in length similar to
Petworth House, being described as a "venerable mansion" in which "many of the apartments are noble". In December 1852, while the family were away for Christmas, the housekeeper was reputed to have drunk too much and awakened to find the entire house in flames. Many valuable items were lost in the blaze. Buchanan Auld House was destroyed in the fire and the 4th duke commissioned
William Burn to design Buchanan Castle to replace it. After the war the building served briefly as the Army School of Education. The roof was removed from the house in 1954 to avoid paying tax on the property and outlying parts of the building were demolished. A number of residential buildings were subsequently built in the castle gardens and grounds. The house is a
category B listed building, and is included on the
Buildings at Risk Register for Scotland. The grounds of the house were included on the
Inventory of Gardens and Designed Landscapes, although they were removed from this listing in 2016. The walls of the house remain intact to their full height and are considered to be in good condition. The ruins are progressively engulfed by trees and plants, and surrounded by a perimeter fence. ==Gallery==