Language serves as both a symbol and a definer of culture. The well-being and integrity of a culture depend heavily on the strength and vitality of its associated language. It is for this reason that the process of language change within particular cultures needs to be monitored and scrutinized. This volume is a map-based analysis of patterns of language change, specifically the Welsh language. It concludes that the prime influences on the language derive from the large-scale socio-economic changes which have taken place in western society as a whole since the end of World War II.