How did patria potestas give Roman fathers legal authority over their families?

In Roman law, patria potestas (Latin for "power of a father") established the male head of a household as the absolute authority over his children and remote descendants in the male line, regardless of their age.12

This legal power granted the father several significant controls:

• Legal Standing: The father was the only person in the family with rights in private law. Consequently, any acquisitions or property obtained by a child under his potestas legally belonged to the father, even if the father allowed the child to treat certain items as their own.12
• Personal Control: Originally, this authority included the power of life and death over his children, including the right to inflict capital punishment.12

Over time, these powers were significantly curtailed. By the classical period, the right to inflict death was reduced to light chastisement, and sons gained the ability to retain earnings from military service. By the era of Justinian, these property rights were further extended to include various professional earnings, while a father's claim to other acquisitions was often reduced to a life interest known as usufruct.12