Nepotism is the act of favoring one's family members in a situation where doing so is considered inappropriate. For instance, a manager in a firm is generally expected to promote the most competent persons, in order that the firm may succeed. For that manager to promote an incompetent relative over a more-qualified employee is nepotism.
The word nepotism comes from the Latin word for nephew. Some biologists have suggested that a tendency towards nepotism is instinctual, a form of kin selection.
Several popes are known to have engaged in nepotism, often by elevating nephews and other relatives to the cardinalate. Often, such appointments were used as a means of continuing a papal "dynasty". For instance, Pope Callixtus III, of the Borgia family, made two of his nephews Cardinals; one of them, Rodrigo, later used his position as a Cardinal as a stepping stone to the papacy, becoming Pope Alexander VI. Coincidentally, Alexander—one of the most corrupt popes—elevated Alessandro Farnese, his mistress's brother, to the cardinalate; Farnese would later go on to become Pope Paul III. Paul also engaged in nepotism, appointing, for instance, two nephews (aged fourteen and sixteen) Cardinals. The practice was finally ended when Pope Innocent XII issued a bull in 1692. The papal bull prohibited popes in all times from bestowing estates, offices, or revenues on any relative, with the exception that one qualified relative (at most) could be made a Cardinal.