The Cangin languages of Senegal remained hidden from linguists for years, and have only recently been seriously documented. This book traces the history of the Cangin languages, and presents a reconstruction of Proto-Cangin through careful application of historical linguistic methods. This is one of few in-depth historical treatments of a West African language family, and takes into account all existing sources, including previously unpublished data from my own work on Noon. The reconstruction of Proto-Cangin reveals a number of important features now obscured in the modern languages, including a surprisingly rich inventory of noun class prefixes, which are of great importance to the study of the world's largest language family, Niger-Congo. Included is a catalogue of over 600 Proto-Cangin reconstructions.