The BBC Ottoman prog mentioned the sultanate succession being a fight off betwen contenders - sons of the many ladies of the harem. They in turn also plotted against possible contenders in the constant scheming of their tedious life. Possible reserve sons for the post were kept in total seclusion in case needed in an emergency - and they usually went dotty.... well that is the tale I wonder if any were evr called on?
 In India, the scheming widows of Maharajas had to take an active part on their husband's funeral pyre to prevent further mayhem in the cut throat business of succession.

Around the world there must be many current heirs to defunct crowns; the Ottoman clan have many princes in waiting but the main one used to be a quiet accountant who lived in Wimbledon - rather like 'Plain Mr Botany B' Our thread on the two princes has suggestions for their eventual resurfacing in quiet mode - but what of other uncrownd heads about the place? I only personally know of lots of princes from old Indian states - and a Mogul or two. All are highly educated professionals in their fields and  extremely unassuming well mannered gentlmen without wealth or clout.

The current heir to the Manchu Ching dynasty of China is apparently 95-year-old Puren Jin Youzhi. He's the half-brother of the last emperor Pu Yi. A retired school-teacher, he lives in Peking.