During the 7th and 8th centuries a number of petty principalities developed in Bretagne. These principalities became subject to Charlemagne early in the 9th century, but in 846, under a leader, Nomenöe, who had united the country against invaders, the Bretons revolted against Charlemagne's grandson, Charles the Bald, and won independence. In the latter part of the 10th century the Bretons acknowledged the rule of the Norman dukes. Geoffrey, count of Rennes, proclaimed himself duke of Bretagne in 922. The dukedom became, through marriage, a possession of Geoffrey Plantagenet, son of Henry II, king of England, in 1171. It reverted to a line of French dukes at Rennes early in the 13th century. In 1491, when Anne of Bretagne, who had inherited the duchy, married Charles VIII, king of France, Bretagne was temporarily united with France. The union became permanent by treaty in 1532, during the reign of the French king Francis I, who had married Claude, daughter of Anne of Bretagne.

Many Bretons still speak their language, and there's rich literature written in Breton, so the language is not considered as becoming extinct or endangered. The language became richer in vowels and consonants as nasals were developed under the French influence. But the traditional Insular Celtic structure of the language is preserved with its rich system of initial mutations, prepositional pronouns and progressive verb forms. Breton is more evoluted than Welsh, perhaps due to the lack of a learned culture. The verb is always at the second place and an extensive use is made of compound tenses, like in French, German and English. It has got a verb "to have", derivated from "to be" but which is no longer considered as a suppletive construction (Kaout). It has two genders (masculine and feminine), distinguished by the way of consonant changes (mutations) and inflect its prepositions. Also Breton borrowed plenty of words from French: mainly the terms of modern civilization. But the language is productive and survivable. It still looks much like Welsh or Cornish, the two mother tongues of modern Bretons. The language itself is divided into four major dialects : Leoneg
around Brest (on which the literary and standard tongue is based ), Tregereg around Treguire, Kerneveg around Quimper and Gwenedeg. The last one differs a lot from the standard language and has its own literary tradition. It could be considered as a language by itself and has been said to descend from Gaulish.