Use of family names in catholic families

Hi all

Trying to determine the reason why my ggg grandfather suddenly started using the name Richmond as a middle name at some point in the 1880s. He certainly wasn’t given the name at birth. The name was subsequently used in the family on numerous occasions right up to today.

My assumption has always been that this must have been a family name from previous generations, maybe he adopted the name after the death of a grandmother? I have been unable to prove this however and am left wondering if there could be another explanation.

Would be grateful for any opinions anyone may have.