information:extraction, linguistic:voice_change
Family names

Family names are simultaneously one of the most important pieces of genealogical information, and a source of significant confusion for researchers.

In many cultures, the name of a person refers to the family to which they belong. This is called the family name, surname, or last name. Patronymics are names that identify an individual based on the father's name. For example, Marga Olafsdottir is Marga, daughter of Olaf, and Olaf Thorsson is Olaf, son of Thor. Many cultures used patronymics before surnames were adopted or came into use. The Dutch in New York, for example, used the patronymic system of names until 1687 when the advent of English rule mandated surname usage. In Iceland, patronymics are used by a majority of the population. In Denmark and Norway patronymics and farm names were generally in use through the 19th century and beyond, though surnames began to come into fashion toward the end of the 19th century in some parts of the country. Not until 1856 in Denmark and 1923 in Norway were there laws requiring surnames.

The transmission of names across generations, marriages and other relationships, and immigration may cause difficulty in genealogical research. For instance, women in many cultures have routinely used their spouse's surnames. When a woman remarried, she may have changed her name and the names of her children; only her name; or changed no names. Her birth name (maiden name) may be reflected in her children's middle names; her own middle name; or dropped entirely. Children may sometimes assume stepparent, foster parent, or adoptive parent names. Because official records may reflect many kinds of surname change, without explaining the underlying reason for the change, the correct identification of a person recorded identified with more than one name is challenging. Immigrants to America often Americanized their names.

Surname data may be found in trade directories, census returns, birth, death, and marriage records.