Beyond the Highland line was another Scotland, wilder, less civilized, and even poorer. The clansmen of the Highlands cared little for the authority of Kirk or king; to them the paternalistic chief, with his power of life and death, was everything. They preserved more of their Celtic inheritance than that, in their speech, in their romantic belief in the supernatural, and in many other ways, while in religion a large section of them were still Roman Catholic. No Sir Walter Scott had yet appeared to give to Lowlanders and Englishmen a glamorous picture of this Highland life; to the outsiders the kilted clansmen in their plaids were dangerous relics of an older and lower civilization. Physical danger and the utter absence of roads in those wild hills discouraged most southerners from venturing beyond the line.
(from A History of England and the British Empire)