In Celtic patronymics, you get named from the line of your forbears. As I'm baptismally a Robert, and my father was also called Robert, I'm Bobby Bob, which is what a lot of people know me as.However, on my radio programme, I usually go a bit further to my grandfather, John, and my great grandfather, William, which gives rise to the patronymic string, Bobby Bob John Billy.
Some people, possibly born out of wedlock, had their mother's name as part of the string, like Juan Nan (Juan is a Manx name pronounced JOO-an, not like the Spanish name of the same spelling) which is John the son of Nan, or Billy Paaie, William the son of Peggy.
Shoh slaynt,
Bobby Bob