Kafes

The Kafes (cage) was part of the Imperial Harem of Topkapı Palace, where possible successors to the throne were kept under a form of house arrest and constant surveillance. Before the kafes system, the brothers of a new sultan would be killed, even boys and infants, to prevent wars between rivals trying to win the throne. With the cafes, these royal candidates lived in a kind of luxurious prison, with nothing refused them until the reigning sultan died. Then the chosen new sultan would take the throne, and everybody else would be killed. Unfortunately, this led to ill-prepared and incompetent sultans because of a lack of experience with anything outside the kafes.