Paterfamilias and family structure?

[Renatus]

Broadly speaking, a paterfamilias had power over his children, of whatever age, and their children as long as he remained alive. Upon his death, his sons became sui juris but his grandchildren fell into the power of their fathers. A grandchild whose father had already died also became sui juris but, if they were too young to manage their own affairs, a tutor, possibly a brother or an uncle on their father's side, could be appointed as their tutor to look after their interests.