Frederick Augustus (1763–1827), Duke of York, became a Freemason in 1787 and was given the honorary title of Past Grand Master of the Grand Lodge of England, one of two governing bodies of Freemasonry in England in the eighteenth and early nineteenth century. The Duke of York’s father, George III, had the power to appoint the Bishop of Osnaburgh (now Osnabrück) in Lower Saxony, Germany.
He elected his son when he was only six months old. The initials that follow his name in the title of this painting relate to his membership of the chivalric Order of the Garter (KG) and Order of the Bath (GCB). In this portrait he is wearing the breast star for the Order of the Garter. Today he is remembered in the nursery rhyme 'The Grand Old Duke of York'.