As described in historical dictionaries

Patronymica Britannica (1860)

TONI. Doubtless from Toeni, a commune in the arrondissement of Louviers, in Normandy, latinized in the XI. century Toenium. Ralph de Todeni or Toni, son of Roger de Toenio, standard-bearer of Normandy, was at the battle of Hastings, In Domesday he appears as tenant in chief in several counties, the head of his barony being Flamstead in Hertfordshire. Robert and Berenger de Todeni, doubtless near kinsmen of Ralph, are also found among the tenants in chief in the great record. The family were ennobled, and became extinct, in one person, the Lord Robert de Toni, temp. Edward I. Upon Robert de Todeni the Conqueror bestowed the lordship of Belvoir, co. Leicester, where he built the castle, afterwards so famous, and made it the head of his barony. His son and heir, William, took the name of De Albini, with the addition of Brito, " to distinguish himself," says Kelham, " from William de Albini, chief butler of the realm."

Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.


BritishSurnames.uk is a Good Stuff website.