Fischers miniature shows the Duke of Sussex, who also held the title Earl of Inverness, in Highland dress of the Royal Stuart tartan with a cap adorned with thistles and with the ribbon and star of the Order of the Garter. It is based on a full-length oil portrait by William Beechey in the Fishmongers Hall, probably exhibited at the Royal Academy in 1816 (no. 112).Prince Augustus, Duke of Sussex, sixth son of George III and Queen Charlotte, married, firstly in 1793, secretly in Rome, and in…