Oval, enamel on copper in a gilt-metal mount and frame, 16.5cm. Signed, inscribed and dated 1847 on the reverse.
The Duke, with thinning hair, is depicted in a red uniform with blue facings and gold lace. He is wearing the chain of the Order of the Garter and the Order of the Bath.
Frederick Augustus was the second son of King George III.
Henry Pierce Bone trained with his father, the noted enamel painter Henry Bone (1755-1834).
He later worked for some years in oils, but reverted to enamels and became enamel painter to Queen Victoria and Prince Albert.