Britain's slimmed-down monarchy has been left vulnerable in wake of cancer diagnoses aol.co.uk - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from aol.co.uk Daily Mail and Mail on Sunday newspapers.
The list of royals who put in the most hours will be of great comfort to King Charles with his sister Anne, the Princess Royal, carrying out almost as many engagements as he has