Legal Definitions - cognatus

In ancient Roman law, a cognatus (plural: cognati) refers to a person who is related to another by blood, meaning they share a common ancestor. This relationship could be traced through either the male or female line, distinguishing it from other forms of kinship that might only recognize relationships exclusively through the male line. The term is also sometimes translated as "cognate relative."

• Example 1 (Direct Lineage):

  A Roman woman named Valeria has a daughter, Claudia. Claudia later has a son, named Marcus. Under the principles of Roman law concerning kinship, Valeria and Marcus would be considered cognati. They are blood relatives who share Valeria as a common ancestor, with the lineage passing through Claudia, a female.

  This example illustrates that the relationship of cognatus recognizes blood ties regardless of whether the descent passes through a male or female link in the family tree.

• Example 2 (Collateral Relatives):

  Two Roman citizens, Aulus and Brutus, are first cousins. Aulus is the son of Julia, and Brutus is the son of Octavia. Julia and Octavia are sisters, sharing the same parents. Therefore, Aulus and Brutus are cognati to each other because they are blood relatives who share a common set of grandparents (Julia and Octavia's parents).

  This demonstrates how the term applies to relatives who are not in a direct line of descent (like parent-child) but are connected through a shared ancestor further up the family tree, such as grandparents.

• Example 3 (Inheritance Context):

  Consider a Roman citizen, Lucius, who dies without leaving a will. His closest surviving relatives are his sister, Antonia, and his maternal aunt, Cornelia (his mother's sister). Both Antonia and Cornelia would be considered cognati to Lucius. Antonia shares parents with Lucius, and Cornelia shares parents with Lucius's mother, meaning they all share common ancestors.

  This scenario highlights the practical application of the term, showing that both direct blood relatives (like a sister) and collateral blood relatives (like a maternal aunt), regardless of the gender of the intervening relatives, fall under the definition of cognati for purposes such as determining heirs in the absence of a will.