The earliest Fonblanques we have found used the prefix ‘de’.
The English branch of Fonblanque
When Abel de Fonblanque sent his sons Jean and Antoine to England in 1727 they became anglicised as John and Anthony Fonblanque. They both became English citizens at different times.
De Fonblanque in England
? Fonblanque petitioned George III to resume the name of de Fonblanque.