Ultimogeniture, also known as postremogeniture or junior right, is the tradition of inheritance by the last-born of a privileged position in a parent's wealth or office. The tradition has been far rarer historically than primogeniture (sole inheritance by the first-born) or partible inheritance (division of the estate among the children).
Ultimogeniture might be considered appropriate in circumstances in which the youngest child had been assigned the role of "keeping the hearth", taking care of the parents and continuing at home, and elder children had had time and opportunity to succeed in the world and provide for themselves. In a variation on the system, elder children might have received a share of land and moveable property at a younger age such as by marrying and founding their own family. Ultimogeniture might also be considered appropriate for the estates of elderly rulers and property owners, whose children were likely to be mature adults.
Those who stand to gain from ignoring the stipulation under ultimogeniture are more likely to have the facility to do so, when compared to other succession laws. For example, under primogeniture tradition, younger siblings stand to gain if they can bypass said tradition; elder siblings, however, have more time and opportunities to gain power, wealth, experience and influence to better solidify their inheritance claim. In ultimogeniture elder siblings, especially the first born of the relevant gender, are heavily incentivized and more empowered to sidestep the tradition, especially if primogeniture inheritance is a culturally familiar concept. This can be achieved through coercion, assassination, fratricide or even patricide to move themselves up the succession order. This may be an explanation as to why primogeniture traditions tend to be more prevalent than ultimogeniture.
