With roots in the middle ages, Spanish surnames have been around since the 12th century. Hispanic surnames can be especially important to genealogists because children are commonly given two surnames, one from each parent. The middle name (1st surname) comes from the father's name (apellido paterno), and the last name (2nd surname) is the mother's maiden name (apellido materno). Sometimes, these two surnames may be found separated by y (meaning "and"), although this is no longer as common as it once was. Recent changes to laws in Spain mean that you may also find the two surnames reversed - first the mother's surname, and then the father's surname.

Origins of Hispanic Last Names
Spanish surnames developed from four major sources:

• Patronymic & Matronymic Surnames - Based on a parent’s first name, this category of surnames includes some of the most common Hispanic surnames. These Hispanic surnames are often formed by adding an -es, -as, -is, or -os (common to Portuguese surnames) or an -ez, -az, -is, or -oz (common to Castilian or Spanish surnames) to the end of the father's name. (Leon Alvarez - Leon son of Alvaro).

• Occupational Surnames - these Hispanic last names are based on the person’s job or trade (Roderick Guerrero - Roderick the warrior or soldier).

• Descriptive Surnames - Based on a unique quality or physical feature of the individual, these surnames often developed from nicknames or pet names (Juan Delgado - John the thin).

• Geographical Surnames - The most common type of Spanish surname, these Hispanic last names are derived from the location of the homestead from which the first bearer and his family lived (Ricardo de Lugo - Ricardo from the town of Lugo).

Origins of 50 Common Spanish Surnames

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