Haven't finished "Sword of State," by Nigel Tranter, but realized that once I familiarized myself with some of the geographic features mentioned in the novel it would enhance my understanding of the novel. The website, Undiscovered Scotland, proved to be a good resource in this endeavor. Rosemarkie was one of the little towns mentioned in the book and it was found here [Undiscovered Scotland]. The name Haliburton evolved from “…Holy Burgh Town" and was mentioned in the same sentence as Kelso Abbey.” Another area mentioned was Lammermuir , a sheep grazing area. Another look at modern day Lammermuir can be found on this blog. Dingwall and Roxburgh were two more places in Scotland mentioned in the novel.
The basis of the book is "...the fascinating 13th century story of Patrick, Master of Dunbar, and his enduring friendship with Alexander II of Scotland." A more detailed of Alexander II's story can be found here. Alexander's father, William I of Scotland, The Lion (1143-1214), used the red lion on yellow as his standard and is a known symbol of present day Scotland.
A history of the Dunbars can be found here, in the "Genealogical Collections Concerning Families in Scotland," by Walter MacFarlane, et al. An updated look at the Dunbars can be found here.