Brittany in France.
It was introduced in the 5th–6th centuries by immigrants from southern Britain. Breton is attested in glosses in Latin manuscripts of the 8th–10th centuries, but no continuous text is known before the 15th century. The modern language is divided into four groups of very diverse dialects; this disunity has hindered efforts to form orthographic and literary standards. Though Breton may have half a million speakers, use of the language is generally thought to be in sharp decline among younger people despite a resurgence of regional particularism in western Europe.