This book presents a comparative, historical account of vowel prosthesis in the Romance languages. Vowel prothesis is one of several types of irregular and sporadic changes that have occurred in Romance, but it has remained poorly studied despite its widespread incidence. It involves the appearance of a non-etymological vowel at the beginning of a word: a familiar instance is initial e in many words in Spanish, as seen for example in the development of Latin spina to Spanish espina 'thorn'. In a wide-ranging account, Professor Sampson distinguishes three major categories of vowel prosthesis in Romance and explores their formal characteristics, their geographical and chronological incidence, and their likely causation. He considers the relationship between the different categories to establish the extent to which they may be viewed as a unitary phenonmenon with a common basis. The book brings together for the first time a substantial body of linguistic and philological material which serves to shed a new light on vowel prothesis in less well-known Romance varieties.