NB: This is a follow on to Spanish Naming Conventions Part 1: The Basics
Examples are Martinez, Rodriguez, Hernandez etc.
The reason for the popularity of these surnames is because they are “patronymic”.
For those unfamiliar with the term, it refers to surnames that are based on the first name of a male ancestor.
In this case, the names are formed by using the father’s name and appending ‘ez to the end to represent “Son of”