The book investigates historical patterns of vowel diphthongization, assimilation and dissimilation induced by consonants - mostly (alveolo)palatals - in Romance. Compiling data from dialectal descriptions, old documentary sources and experimental phonetic studies, it explains why certain vowels undergo raising assimilation before (alveolo)palatal consonants more than others. It also suggests that in French, Francoproven al, Occitan, Rhaetoromance...