Through marriage and royal patronage it acquired lands and influence with the major families/clans. Examples would be Stewarts/Stuart of, Atholl, Barclye, Buchan, Bute, Rothesay and others.

Walter Stewart, 6th High Steward by marrying Marjorie Bruce, daughter of Robert the Bruce founded the Royal  House of Stewart which came to the throne with Robert II (1371). It ended in 1707 on the Act of Union in Queen nn’s reign.  The Jacobite uprisings in the 18th century, the “Fifteen” and the “Forty Five”, were lead by Charles Edward Stuart (Bonnie Prince Charlie). He was the exiled claimant to the throne.

Stewarts fought mostly for the Jacobites many of them having their estates forfeited. Today the Stewart clan does not have a clan chief . The Earls of Galloway are now considered to be the principal Stewart branch, their crest, motto and arms are used by the clan. Of the other two  'Stewart' clans that are recognised, Stuart of Bute and Stewart of Appin, the former is the only one with a recognised chief.  The Queen is the chief of Chiefs and as a result the Royal Stewart and the Hunting Stewart tartans are seen as "universal" tartans so are used by anyone without clans or a tartan.