Colonels-in-Chief were Royal patrons. They provided a link between the Regiment and the Royal Family. This role was symbolic of the monarch's role as leader of the armed forces.
The position of Colonel-in-Chief is distinct from that of Colonel of the Regiment. They do not have an operational role. They are however kept informed of all important activities of the regiment, and pay occasional visits to its operational units.
The Black Watch has had only three Colonels-in-Chief during its history:
His Majesty King George V
Her Majesty Queen Elizabeth The Queen Mother
His Royal Highness The Prince Charles Duke of Rothesay
In 2006, Queen Elizabeth became Colonel-in-Chief of The Royal Regiment of Scotland. The Duke of Rothesay remains Royal Colonel of The Black Watch, 3rd Battlaion The Royal Regiment of Scotland.
Images (from top): Colonel-in-Chief uniform of George V; Queen Elizabeth The Queen Mother as Colonel in Chief, 1937; The Duke of Rothesay by Georgina Barclay, in Colonel-in-Chief uniform.