Without a firm principle of primogeniture, Delhi sultans weren’t very good at establishing dynasties. And many did not last long. Knowing this, one wise sultan took no chances: he kept his son and heir away from the court, made sure the boy was educated well under the supervision of a respected maulvi, and that he did not develop any of the usual bad habits. Then, this conscientious father died. His son became the sultan, instantly forgot his studies, fell greedily into all the vices from which he had been separated, and in short order found himself sick and paralysed by syphilis. Eventually, a usurper took courage, entered the royal chamber, rolled the helpless young man up in his rug, and tossed him out of the window into the river below.