Six case histories establish a typology of the rise, recession, and hidden survival of Western prestige languages: Greek in Rome, Latin in Byzantium, Anglo-Norman/Anglo-French, Medieval Latin, Alamode in Germany, and Puristic in modern Greece. A pattern evolves: the diglossic system of higher and lower levels, which reflects a class society, is strangled by the low level, which expands under popular pressures. The elite language declines but it does not disappear altogether ; rather it compromises with the vernacular, and from their fusion the standard language is born. In short, the languages of the educated are explained as vernaculars refined by the survival of former prestige languages.