Brechin Castle and gardens in Angus will go on the market in the Spring.
James Ramsay, 17th Early of Dalhousie and chief of Clan Ramsay, said he and his wife will move into a smaller house in the grounds following the sale.
The laird also owns the substantial Dalhousie Estates, which stretches deep into the Angus Glens, but the large-scale rural operation will not be affected by the castle’s sale.
He said: “Brechin Castle has been the family home for many generations but the running costs are a significant overhead for the family business.
“We have therefore taken the decision to put the house and gardens up for sale and my wife and I will move to another smaller house on the estate once the sale is complete.
“The rest of the estate at Brechin, Edzell and Invermark, and all our business enterprises, including Brechin Castle Centre and Peggy Scotts (a restaurant), as well as our farming operation, forestry, game and property letting, will continue to operate as at present and, other than those who are employed at Brechin Castle itself, there will be no change in our present staffing, which now numbers around 90 full and regular part time staff.
“Indeed, we will continue to explore opportunities to expand and diversify the family business.”
Brechin Castle, which stands above the River Southesk, dates back to the 13th Century but it was turned into a fine country home in the early 18th Century.
The property has had a role in several significant events in Scottish history.
The old castle was captured by Edward I in 1303 following a three-week standoff led by Sir Thomas Maul.
It was forfeited after James Maule, the fourth and last Earl of Panmure, led support for the 1715 Jacobite rising. At the Mercat Cross in Brechin, he proclaimed that James Francis Edwart Stuart - the Old Pretender - was King James VIII
Panmure was captured after fighting at the Battle of Sheriffmuir but escaped to the Continent. His brother, Harry, was later allowed to retrieve the family properties.