Cornish is a Southwestern Brittonic language of the Celtic language family. Along with Welsh and Breton, Cornish descends from Common Brittonic, a language once spoken widely across Great Britain. For much of the medieval period Cornish was the main language of Cornwall, until it was gradually pushed westwards by the spread of English. Cornish remained a common community language in parts of Cornwall until the mid-18th century, and there is some evidence for traditional speakers persisting into the 19th century.
Cornish became extinct as a living community language in Cornwall by the end of the 18th century; knowledge of Cornish persisted within some families and individuals. A revival started in the early 20th century, and in 2010 UNESCO reclassified the language as critically endangered, stating that its former classification of the language as extinct was no longer accurate. The language has a growing number of second-language speakers, and a very small number of families now raise children to speak revived Cornish as a first language.
Cornish is currently recognised under the European Charter for Regional or Minority Languages, and the language is often described as an important part of Cornish identity, culture and heritage. Since the revival of the language, some Cornish textbooks and works of literature have been published, and an increasing number of people are studying the language. Recent developments include Cornish music, independent films, and children's books. A small number of people in Cornwall have been brought up to be bilingual native speakers, and the language is taught in schools and appears on street nameplates. The first Cornish-language day care opened in 2010.