This book presents a comparative, historical account of vowel prosthesis in the Romance languages. Vowel prosthesis is one of several types of irregular and sporadic sound change that have occurred in Romance, but it has remained poorly studied despite its widespread incidence. It involves theappearance 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 vowelprosthesis 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 phenomenon with a common basis.The book brings together for the first time a substantial body of linguistic and philological material which serves to shed new light on vowel prosthesis in standard varieties such as French and standard Italian while also calling attention to important instances of prosthesis in less well-knownRomance varieties.