You are looking at a parish register from 1750. It registers the birth of Mary, daughter of John Wilson als Brooks. What does this mean?
First, als is the abbreviation for ALIAS. This is nothing to do with disreputable conduct. Alias is a Latin word meaning at another time. So the register tells us that John Wilson was known at another time as John Brooks. John has therefore changed his surname at some point. Now that is a very important matter to a genealogist.
There were a number of reasons why a person might change a surname. The most frequent related to illegitimacy. John Wilson’s mother may have been Nancy Brooks, and his father may have been George Wilson. At. John’s baptism, he would have been given his mother’s surname because an illegitimate child was considered not to belong legally to its father’s family. If his parents subsequently married each other, he would probably assume his father’s surname. If not, he could still assume his father’s surname, with or without his father’s consent. His father could also acknowledge parentage and treat him as his own son. For inheritance purposes, his father could make him part of the family, by effectively adopting him.
Inheritance also played a part in other name changes. Sometimes, a wealthy person had no children, but agreed that if a favourite relative or friend would assume and continue the family name, then that person would inherit the wealthy person’s assets. This was quite common among the aristocracy, who would sometimes transfer titles as well as wealth.
Another event giving rise to a change of name was remarriage. A widow with children would remarry, and the children would take the surname of their stepfather, particularly, if they were very young at the date of remarriage, or if he adopted them.
Sometimes, there was a reason to display one’s ancestry by way of one’s surname. If the daughter of the Duke of Wellington married plain Mr. Brown, the children might wish to be called Brown als Churchill, or as we might join surnames, Brown-Churchill or Churchill-Brown. The double name might continue for several generations. Similarly, if a married woman was referred to in a legal document, it might be considered necessary to mention her family origins. She took her husband’s name automatically on marriage, but might be shown as Mrs. Brown als Churchill in the legal document.
Prior to 1926, there was no formal mechanism for recording adoption in England. Adoptions could be done by a formal deed transferring a child from the natural parents to the adopting parents, and this would simply be kept among the family papers. In some cases, adoptions were done by verbal agreement, not recorded anywhere.
Changes of name were done with similar informality, although for the wealthy aristocracy, it became common in the mid 1600s to create an official record. A private Act of Parliament could be obtained, and this procedure continued until 1907. Instead, the King could be asked to issue a Royal Licence, and from the 1700s onwards, these were usually published in the London Gazette.
Another method of change of name was a deed poll. (A deed poll is a document involving only one person, so unlike a normal deed with indented edges enabling copies to be matched for verification, the edges of a deed poll are poll, meaning smooth.) From 1851, a deed poll could be filed in the Close Rolls of the Court of Chancery. Prior deed polls are among private papers.
Other persons changed their names by advertising in the press, or making sworn statement in front of the Justice of the Peace.
The parish register information about John Wilson being also John Brooks may be the only record of that name change that you can now find. Some parish register entries can be quite explicit. Consider the following baptism, from the registers of St. Leonard’s, Langho - a chapel in the eastern part of Lancashire: 1766 Feb2 Nancy alias Nancy Aspin, daughter of Betty Walsh of Blackburn, unlawfully begotten.
The registers do not show anyone else with the surname Aspin in this chapelry. If Nancy were an ancestor of mine, this entry would give me a very good start in looking at the parish Vestry records to confirm parentage; or the Quarter Sessions records for a Maintenance Order against the father; or the Archdeacon’s Presentments to see who was punished for fornication.
We should be very grateful to those parish clerks who included alias names in their registers. So many pedigrees would end abruptly without them.