Nicknames, be they diminutives of an existing name, a reflection of a person’s appearance or habits, a childhood name that lingers into adulthood, or given for any other reason, can cause difficulty for us a researchers.
If a person is commonly known by a nickname, for whatever reason, it could be that they will have records under that nickname. As researchers, if we don’t know what that nickname was – or don’t check for the person under that nickname – we may miss out on finding records.
Many nicknames were based on the person’s actual name, and again we as researchers need to be aware of them and keep them in mind. For example, if you don’t know that Polly was a diminutive of Mary or that Nellie was a diminutive of Ellen and Eleanor and Helen, you may struggle to find your ancestors’ entries. Harry for Henry, Bill for William, Fred or Alf for Alfred, Dick for Richard, Charlie or Lottie for Charlotte, Maggie, Meg or Maisie for Margaret. Elizabeth was another extremely common name with multiple diminutives - Eliza, Liz, Lizzie, Betty, Betsy, Beth, Bessie, Lisbeth, Liza - the list goes on.
A nickname can be so commonly used that the person’s actual name is virtually forgotten. I have one female ancestor, baptised Elizabeth, who was known throughout her life as Betsy. This was the name she used in census records, her children's birth/baptism records and on her death certificate and burial record. The only time I can ever find her referred to as Elizabeth is at her baptism.
So if your ancestor was known by a nickname (and you are aware of it), remember to search for them under both their given name and their nickname. You never know what you might find.