Aide-de-camp
An
aide-de-camp is a title in the
peerage system (which infers the post-nominal letters
ADC) which means that the so-honoured person is considered a personal assistant to the monarch of the particular country he or she is a subject of; the first
aide-de-camp is the foremost personal aide.
For example, Prince Andrew, Duke of York of the British Royal Family is currently the aide-de-camp to his mother, Queen Elizabeth II. Similarly, Geraud Duroc was made an aide-de-camp to Napoleon in 1796, and first aide-de-camp in 1798.