The Gaelic word clann means primarily children. Clans are referred to in the reign of David I (1124–53) in the Book of Deer, where there are references to the toiseachs of the Clans Morgan and Canan. A toiseach was a royal official. Mackintoshes are Clann an Toiseach, literally ‘the toiseach's children’.
Clans Canan and Morgan did not survive. Continual flux, constant rise and fall seems to have been typical of Scottish clans. Most Highland clans were in origin Gaelic communities onto which feudal structures were grafted. Especially in the province of Moray, there were also feudal groups, such as the Frasers, Chisholms, Grants, and Rosses, which adopted clanship.
From feudalism a clan chief gained the concept of absolute ownership of land, and succession by primogeniture. Female heirs, or wardship by a superior of a male minor, could threaten the tribal identity. Control of the marriage of a female heiress by the cadet branches of the chiefly house, and the office of tutor or guardian within the clan, were partial answers. Kinship was largely bogus for the bulk of a clan, who only began to use surnames very late.
After the forfeiture of the lordship of the Isles in 1493 broke the Clan Donald into smaller MacDonald clans, three great clans dominated Highland history. These were the Gordons in the north‐east, the Mackenzies in the northern Highlands and Hebrides, and Clan Campbell in the west. Highland clans became deeply distrusted after a century of bloody intervention in Lowland politics between 1644 and 1746. After the last Jacobite rebellion legislation destroyed them as military, jurisdictional, and cultural units. Market economics and clearances completed the job.