Keiss Castle is a partially ruined castle which was replaced by the Keiss House around 1755. The old castle was built possibly on the site of an earlier fort in the late 16th or early 17th century by George 5th Earl of Caithness (1582-1643). It seems the castle was in existence in 1623 when James I commissioned Sir Robert Gordon to enter Caithness with an armed force. The 7th Earl died in the castle in 1698 but it is reported that the castle was ruinous in 1700 and in 1726 as being in repair with 'at the side of it a convenient house lately built'. The estate was purchased by Sir William Sinclair, 2nd Baronet of Dunbeath early in the 18th century and in 1752 Keiss became his family seat.
The current house was built about 1755 but had to be sold in 1765 because of financial difficulties to the Sinclairs of Ulbster. This Category B Listed Baronial mansion was altered to its current form on the instructions of Col. K Macleay by David Bryce in 1860, during which it was extended in the Scottish baronial style. It was then sold to the Duke of Portland in 1866. Also included in the listing is the Walled garden to the NE of the house and the gate lodge and gate piers with cast-iron carriage gates installed in the 1860 alterations.
References:The Château du Haut-Koenigsbourg is situated in a strategic area on a rocky spur overlooking the Upper Rhine Plain, it was used by successive powers from the Middle Ages until the Thirty Years' War when it was abandoned. From 1900 to 1908 it was rebuilt at the behest of the German kaiser Wilhelm II. Today it is a major tourist site, attracting more than 500,000 visitors a year.
The first records of a castle built by the Hohenstaufens date back to 1147. The fortress changed its name to Koenigsburg (royal castle) around 1157. The castle was handed over to the Tiersteins by the Habsburgs following its destruction in 1462. They rebuilt and enlarged it, installing a defensive system designed to withstand artillery fire.
The fortification work accomplished over the 15th century did not suffice to keep the Swedish artillery at bay during the Thirty Years War, and the defences were overrun.