All Stewarts, says the old proverb, are not "sib" (related) to the king. There are no legitimate descendants in the male line of the Stewart Kings, but a number of families trace their descent from ancesters of the royal house, and so can claim kinship with them. Walter, a younger son of the steward who was first to adopt the surname, and great uncle of Marjorie Bruce's husband, founded the first cadet branch of the Stewarts; but the earldom of Menteith which he acquired by marriage was ultimately merged with the royal dukedom of Albany.

The largest group of legitimate but pre-royal branches of the house of Stewart was founded by Sir John, brother of James the steward of and uncle of Marjorie's husband, who was the companion of Wallace and fell while marshalling the Scots archers at Falkirk in 1298. He acquired the Berwickshire estate at Bonkyl (or Buncle) by marrying the heiress, and three of his sons founded noble families-Sir Alexander of Bonkyl, Sir Alan of Dreghorn in Ayershire, and SirJames Pearston in Ayershire. By the end of Bruce's reign the senior line held the earldom of Angus, but before the century was out this had been transmitted through heiress to the Douglasses.

From Sir John's second son Alan (killed at Halidonhill in 1333) came the Stewarts of Damley, later Earls of Lennox. The head of this family was killed in 1439 by Sir Thomas Boyd of Kilmarnock "for old feud that was betwixt thame" and his brother "manfullie sett upoun" and killed Sir Thomas in revenge.In the next generation, having acquired half the earldom of Lennox by marriage, Sir John Stewart assumed the title in 1473. The fourth Stewart earl was the father of Henry Lord Damley, who married Mary Queen of Scots, was given the title of king, and was father of James VI. While James remained childless a dynastic quarrel arose with the Hamiltons, whose descent from a sister of James III made them the nearest heirs to the throne until the birth of Prince Henry in 1594. The title, raised to a dukedom for Esme Stuart, seigneur d'Aubigny, returned at the 6th duke's death in 1672 to Charles II, who conferred it to his son by Louise de Keroualle.

The male line of Lennox, though not the title, was extinguished with the death in 1672 of Henry cardinal Duke of York, brother of Prince Charles Edward, and since then the Earls of Galloway have been the senior legitimate representatives in the male line of the ancient High Stewarts of Scotland. They are derived from the first offshoot from the house of Darnley, Sir William of Jedworth, sheriff of Teviotdale, who figures in the national records from 1385 to 1402. His son acquired Garlies near Newton Stewart by marriage with a Stewart cousin, and on several occasions, the Lennox family acknowledged their kinship when the laird of Garlies was made a peer in 1607 by James VI (who was head of the house of Lennox, through his father, as well as king), it was in recognition of many years of good service and of his uniterrupted descent from the ancient noble family of Lennox. Lord Garlies was made Earl of Galloway in 1623, and a cadet branch, who were for many years hereditary provosts of Glasgow held the title of Lords Blantyre.

From Sir James Stewart of Pearston, who fell at Hallidon Hill with his brother Alan, through his son Sir Robert of Innermeath, descended the Stewarts of Atholl, Buchan and Traquair, the Lords of Lorn, the stewarts of Appin and of Grandtully, and some of the other highland families of the name. The Stewart Society, of which the Earl of Galloway is the honorary president, was founded in 1899 with patriotic,genealogical, historical and philantropic objectives. It has erected memorial gates at Bathgate to Walter the High Steward, immediate progenitor of the royal house, a statue near Fortingall to General David Stewart of Garth, historian of the highland regiments and writer on the Highlands generally, and other memorials. It owns the island of Inchmahome in the Lake of Menteith, where some of the oldest effigies lie in the priory ruins among the great Spanish chestnut trees, recalling the branches which from the earliest times have spread from the main Stuart stem.

The Stewarts in Scotland are essentially a Lowland Family with Highland and Island offshoots, and it was Robert II who consolidated the achievements of his Royal grandfather, Robert the Bruce. The Stewarts were also a remarkably prolific family and spawned innumerable offspring, legitimate and otherwise. Sir John Stewart of Bonkyl (d.1298) for example, had seven sons, among them Alexander, Earl of Angus, Alan, Earl of Lennox, Walter, ancestor of the earls of Galloway, and James, ancestor of the earls of Buchan and Traquair, as well as the Lords of Lorne and Innermeath. Since the demise of the Lennox Branch, the earls of Galloway have been regarded as the senior representatives of the ancient line of the High Stewards of Scotland.