The use of a surname is relatively new in history and was adopted in order to legally distinguish two individuals with the same first name.
At first, these last names were not passed down to the next generation.
The Chinese were among the very first cultures to adopt the use of hereditary surnames about 5000 years ago. In Europe, surnames weren’t used until the 10th or 11th centuries AD in Venice. Gradually throughout Europe, all nobility and gentry adopted surnames until eventually surnames were used by all Europeans of all classes.