Brett Family History

English and French: ethnic name for a Breton, from Old French bret. The Bretons were Celtic-speakers driven from southwestern England to northwestern France in the 6th century ad by Anglo-Saxon invaders; some of them reinvaded England in the 11th century as part of the army of William the Conqueror. In France and among Normans, Bretons had a reputation for stupidity, and in some cases this name and its variants and cognate may have originated as derogatory nicknames. The English surname is most common in East Anglia, where many Bretons settled after the Conquest. In Scotland it may also have denoted a member of one of the Celtic-speaking peoples of Strathclyde, who were known as Bryttas or Brettas well into the 13th century.

Source: Dictionary of American Family Names ©2013, Oxford University Press