A more thorough explanation:

Capitis aestimatio is a Latin term that means "valuing of a head." In history, it referred to a monetary estimate of a person's life, which was used to assess a penalty for the person's slaying. This was also known as wergild, which was the fixed value of a person's life. It was the amount that a homicide's kindred had to pay to the kindred of the slain person to avoid a blood feud.

For example, if someone killed another person, their family would have to pay a certain amount of money to the family of the person who was killed. This was to compensate for the loss of the person's life and to prevent a blood feud between the two families. The amount of money paid was determined by the person's social status and other factors.

Another example is the effusio sanguinis, which was a legal term used in ancient Rome. It referred to the shedding of blood, and it was used to determine the severity of a crime. If someone shed blood intentionally, they would have to pay a fine or face other penalties.

These examples illustrate how capitis aestimatio was used in history to value a person's life and to determine the penalty for taking someone's life. It was a way to prevent blood feuds and to ensure that justice was served.