There has been a royal castle on Castle Rock, Edinburgh, since at least the reign of David I (reign 1124 to 1153).
The Royal Stewarts lived in Edinburgh Castle from the first Stewart king, Robert II; and the site continued to be a royal Stewart residence until 1633. However, when James VI (Stewart) of Scotland, who was born in Edinburgh Castle, became James I of Britain in 1603, he moved to London.
Blair Castle is said to have been started in 1269 by John I Comyn, Lord of Badenoch (died c. 1275), a northern neighbour of David I Strathbogie, Earl of Atholl (died 1270). Comyn started building on the Earl's land while the Earl was away on crusade. Upon Strathbogie's return, he complained about the interloper to King Alexander III, won back his land, and incorporated the tower built by Comyn into his own castle. Blair Castle has belonged to the Earls, Marqueses, and Dukes of Atholl since it was built. This includes the Stewarts of Atholl who were Earls of Atholl from 1342 until 1625.
John Murray, son of the second Earl of Tullibardine, was created Earl of Atholl in 1629, because his mother was Atholl heiress Dorothea Stewart. The title, and Blair Castle, has remained in the Murray family ever since.
Pitsligo Castle would certainly have been known to Frank and Georgina Cruickshank. Located to overlook the Buchan coast of Aberdeenshire, it is 1/2 mile (1 Km) southeast of Rosehearty.
The tower house, near the centre of the castle, was built around 1424 by the Fraser family of Philorth. Ownership passed to the Forbes family who added the other buildings and extended the castle to approximately its current layout.
Pitsligo Castle was sacked by English King George I's troops after the 1745 defeat at Culloden, and allowed to decay.
Multiple views are found here: https://canmore.org.uk/site/20801/pitsligo-castle
There is a pretty amusing story about Pitsligo Castle when you
Sign points the way to the ruins of Kincardine Castle and Borough.
Click for the story of Kincardine Castle and Borough